Blame etc/README.md

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> N.B. If you're interested in building Midipix using this script, please join
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the project's IRC channel #midipix on Libera and ask for the address of the
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internal repositories required in order to build Midipix.
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> N.B. Due to the present state of the (largely) automated package upstream
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updates integration script and, despite frequent contributions, lack of
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human resources, it bears mentioning that the 3rd party packages built
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and distributed by this script are often not up to date with their resp.
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upstream and *may* hence be **insecure**. It is advised that this be taken
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into account when deploying and using Midipix distributions.
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[//]: # "{{{ Table of contents"
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# Table of Contents
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1. [What is Midipix, and how is it different?](#1-what-is-midipix-and-how-is-it-different)  
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2. [Building and deployment](#2-building-and-deployment)  
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	2.1. [Building, installing, and using a Midipix distribution](#21-building-installing-and-using-a-midipix-distribution)  
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		2.1.1. [Build-time dependencies](#211-build-time-dependencies)  
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			2.1.1.1. [Alpine-specific notate bene](#2111-alpine-specific-notate-bene)  
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	2.2. [Deployment](#22-deployment)  
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	2.3. [System requirements](#23-system-requirements)  
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	2.4. [Troubleshooting](#24-troubleshooting)  
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3. [Common concepts and tasks / FAQ](#3-common-concepts-and-tasks-faq)  
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	3.1. [Common tasks](#31-common-tasks)  
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	3.2. [Adding a package](#32-adding-a-package)  
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	3.3. [Addressing build failure](#33-addressing-build-failure)  
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	3.4. [Package archive files and Git repositories](#34-package-archive-files-and-git-repositories)  
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	3.5. [Patches and ``vars`` files](#35-patches-and-vars-files)  
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4. [Reference](#4-reference)  
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	4.1. [Build steps](#41-build-steps)  
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	4.2. [Build variables](#42-build-variables)  
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	4.3. [File installation DSL](#43-file-installation-dsl)  
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	4.4. [Package variables](#44-package-variables)  
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		4.4.1. [Package variable types](#441-package-variable-types)  
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		4.4.2. [Package variables](#442-package-variables)  
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	4.5. [Fault-tolerant & highly optimised 3D laser show-equipped usage screen](#45-fault-tolerant--highly-optimised-3d-laser-show-equipped-usage-screen)  
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	4.6. [``pkgtool.sh``](#46-pkgtoolsh)  
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	4.7. [Bourne shell coding rules](#47-bourne-shell-coding-rules)  
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5. [References](#5-references)  
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[//]: "}}}"
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[//]: # "{{{ 1. What is Midipix, and how is it different?"
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## 1. What is Midipix, and how is it different?
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midipix is a development environment that lets you create programs
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for Windows using the standard C and POSIX APIs. No compromises made,
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no shortcuts taken.  
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If you are interested in cross-platform programming that reclaims
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the notion of write once, compile everywhere; if you believe that the
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'standard' in the C Standard Library should not be a null signifier;
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and if you like cooking your code without #ifdef hell and low-level
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minutiae, then this page is for you.  
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midipix makes cross-platform programming better, simpler and faster,
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specifically by bringing a modern, conforming C Runtime Library to the
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Windows platform. While the idea itself is not new, the approach taken
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in midipix to code portability is radically different from that found
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in other projects.  
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*(reproduced from [[2](https://midipix.org/#sec-midipix)])*
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[Back to top](#table-of-contents)
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[//]: "}}}"
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[//]: # "{{{ 2. Building and deployment"
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## 2. Building and deployment
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[//]: # "}}}"
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[//]: # "{{{ 2.1. Building, installing, and using a Midipix distribution"
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### 2.1. Building, installing and using a Midipix distribution
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A Midipix distribution consists of the following:
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* the native Midipix toolchain, consisting of perk, gcc, its dependencies,
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  and binutils,
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* musl, a lightweight, fast, simple, and free libc[[1](https://www.musl-libc.org/faq.html)] used by Midipix,
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* the Midipix runtime components that bridge the gap between the libc and the
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  executive subsystems of all Windows NT-derived Windows OS starting with and
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  including Windows XP, and
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* a steadily increasing number of 3rd party open source packages, as expected in
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  any modern POSIX-compliant \*nix environment, including GNU coreutils, shells,
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  libraries such as ncurses, libressl, as well as Perl and Python.
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Install the build-time dependencies listed in section [2.1.1](#211-build-time-dependencies),
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clone this repository (e.g. ``git clone https://dev.midipix.org/build/midipix_build``)
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and run the following command line:
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```shell
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./build.sh -a nt64 -b release -D zipdist -P -v
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```
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By default, the build will take place within ``${HOME}/midipix/nt64/release``
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and package archive files and/or Git repositores will be downloaded into
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``${HOME}/midipix/dlcache``. Consult sections [4.2](#42-build-variables) and
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[4.4](#44-package-variables) for the list of available build/package variables
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and how to override them.  
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Parallelisation is enabled by the above command line for both packages that can
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be built independently of each other and ``make(1)`` via ``-j``, limited to the
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amount of logical processors on the build host divided by two (2).
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 2.1.1. Build-time dependencies"
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### 2.1.1. Build-time dependencies
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* **Alpine Linux**:
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  binutils bison bzip2 cmake coreutils curl findutils g++ gawk gcc git grep gzip libc-dev linux-headers lzip m4 make musl-dev net-tools patch perl perl-xml-parser procps sed tar util-linux util-linux-dev wget xz zip
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* **Arch Linux**:
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  binutils bison bzip2 cmake coreutils curl findutils gawk gcc git grep gzip lzip m4 make net-tools patch perl perl-xml-parser procps-ng sed tar util-linux util-linux-libs wget xz zip
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* **Debian/-derived Linux**:
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  binutils bison bzip2 cmake coreutils curl findutils g++ gawk gcc git grep gzip hostname libc6-dev libxml-parser-perl lzip m4 make patch perl procps sed tar util-linux uuid-dev wget xz-utils zip
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* **Gentoo Linux**:
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  binutils bison bzip2 cmake coreutils curl findutils gawk =gcc-7.5.0-r1 dev-vcs/git grep gzip lzip m4 make patch perl dev-perl/XML-Parser procps sed tar util-linux libuuid wget xz-utils zip
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* **OpenSUSE Linux**:
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  binutils bison bzip2 cmake coreutils curl findutils gawk gcc gcc-c++ git grep gzip hostname linux-glibc-devel lzip m4 make patch perl perl-XML-Parser procps sed tar util-linux libuuid1 wget xz zip
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#### The distro matrix:
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|  Alpine Linux:  |    Arch Linux:     |   Debian/-derived Linux:   |    Gentoo Linux:    |  OpenSUSE Linux:  |
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| --------------- | ------------------ | -------------------------- | ------------------- | ----------------- |
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| binutils        | binutils           | binutils                   | binutils            | binutils          |
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| bison           | bison              | bison                      | bison               | bison             |
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| bzip2           | bzip2              | bzip2                      | bzip2               | bzip2             |
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| cmake           | cmake              | cmake                      | cmake               | cmake             |
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| coreutils       | coreutils          | coreutils                  | coreutils           | coreutils         |
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| curl            | curl               | curl                       | curl                | curl              |
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| findutils       | findutils          | findutils                  | findutils           | findutils         |
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| g++             | -                  | g++                        | -                   | gcc-c++           |
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| gawk            | gawk               | gawk                       | gawk                | gawk              |
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| gcc             | gcc                | gcc                        | =gcc-7.5.0-r1       | gcc               |
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| git             | git                | git                        | dev-vcs/git         | git               |
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| grep            | grep               | grep                       | grep                | grep              |
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| gzip            | gzip               | gzip                       | gzip                | gzip              |
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| -               | -                  | hostname                   | -                   | hostname          |
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| libc-dev        | -                  | libc6-dev                  | -                   | linux-glibc-devel |
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| linux-headers   | -                  | -                          | -                   | -                 |
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| lzip            | lzip               | lzip                       | lzip                | lzip              |
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| m4              | m4                 | m4                         | m4                  | m4                |
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| make            | make               | make                       | make                | make              |
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| musl-dev        | -                  | -                          | -                   | -                 |
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| net-tools       | net-tools          | -                          | -                   | -                 |
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| patch           | patch              | patch                      | patch               | patch             |
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| perl            | perl               | perl                       | perl                | perl              |
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| perl-xml-parser | perl-xml-parser    | libxml-parser-perl         | dev-perl/XML-Parser | perl-XML-Parser   |
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| procps          | procps-ng          | procps                     | procps              | procps            |
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| sed             | sed                | sed                        | sed                 | sed               |
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| tar             | tar                | tar                        | tar                 | tar               |
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| util-linux      | util-linux         | util-linux                 | util-linux          | util-linux        |
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| util-linux-dev  | util-linux-libs    | uuid-dev                   | libuuid             | libuuid1          |
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| -               | vi                 | -                          | -                   | -                 |
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| wget            | wget               | wget                       | wget                | wget              |
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| xz              | xz                 | xz-utils                   | xz-utils            | xz                |
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| zip             | zip                | zip                        | zip                 | zip               |
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> N.B. Busybox is not supported. Awk implementations other than GNU Awk are not supported.  
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> N.B. clang is not supported.  
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 2.1.1.1. Alpine-specific notate bene"
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#### 2.1.1.1. Alpine-specific notate bene
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Some packages (*coreutils*, *grep*, and *tar*, among others) override Alpine's
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BusyBox utilities of the same name, as the latter are either non-conformant or
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defective.
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 2.2. Deployment"
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### 2.2. Deployment
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On successful completion of the build, a ZIP archive containing the Midipix
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distribution will be created inside ``${PREFIX}`` (see section [4.2](#42-build-variables).)
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Create a directory on the target machine and extract the contents of the distribution
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ZIP archive into it, run ``bash.bat``, and then ``/install.sh`` inside the resulting
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self-contained Midipix installation shell window.  
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Make sure to consult the notate bene below:  
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> N.B. The pathname of the target directory containing ``bash.bat`` and all other
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distribution files must not contain whitespaces.  
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> N.B. The Midipix installer defaults to ``/dev/fs/c/midipix (C:\midipix)``. If left
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unchanged, the distribution ZIP archive must not be extracted into a directory of the
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same pathname.  
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> N.B. The user installing and using Midipix must have been delegated the ``SeCreateSymbolicLinkPrivilege``
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("Create symbolic links") privilege[[3](https://docs.microsoft.com/en-us/windows/security/threat-protection/security-policy-settings/user-rights-assignment)] and additionally be a non-administrator account
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owing to the UAC-related filtering policy of tokens introduced by Windows Vista[[4](https://docs.microsoft.com/en-us/previous-versions/dotnet/articles/bb530410%28v%3dmsdn%2e10%29)].  
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> N.B. On Windows 10 and 11, Windows Defender as well as SmartScreen must be disabled.
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 2.3. System requirements"
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### 2.3. System requirements
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The following build-time system requirements are assessed on build hosts
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equipped with the following hardware at minimum:
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* Intel(R) Xeon(R) CPU W3520 @ 2.67GHz (8 cores)
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* 7200 RPM SATA 3.1 HDD
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* 6 GB RAM
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| Target architecture | Build kind | Distribution kinds selected | Average build time | Disk space required | Peak RAM usage |
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| ------------------- | ---------- | --------------------------- | ------------------ | ------------------- | -------------- |
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| nt64                | debug      | (none)                      | 2 hours            | 57.62 GB            | 3.55 GB        |
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| nt64                | release    | (none)                      | 1 hours 45 minutes | 36.51 GB            | 3.21 GB        |
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Package archive files and/or Git repositories additionally consume at least
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1.82 GB.
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*(last update: Thu, 05 Mar 2020 09:25:41 +0000)*
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These are the Midipix distribution disk space system requirements:
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| Target architecture | Build kind | Distribution | Installation directory | Archive file |
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| ------------------- | ---------- | ------------ | ---------------------- | ------------ |
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| nt64                | debug      | 7.3 GB       |  2.3 GB                | 2.1 GB       |
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| nt64                | release    | 3.2 GB       |  913 MB                | 830 MB       |
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The installation directory and archive file may be safely deleted post-installation.
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*(last update: Thu, 07 Jan 2021 18:20:06 +0000)*
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 2.4. Troubleshooting"
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### 2.4. Troubleshooting
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Midipix presently provides, inter alia, strace-like functionality via
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ntctty's logging capabilities. This is available both through the regular
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``strace(1)`` command as distributed, which however **must** be provided
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with an absolute pathname without consideration for ``${PATH}``, as well
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as directly via ``ntctty.exe`` for a session by running ``ntctty.exe``
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with the ``--log-level 7`` option, e.g.:
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```shell
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$ #strace ls -la /        # (incorrect, relative pathname)
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$ strace /bin/ls -la /    # (correct, absolute pathname)
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$ ntctty.exe --log-level 7 -e /bin/ls -la /
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$ ntctty.exe --log-level=7 -e /bin/ls -la /
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$ ntctty.exe --log-level 7 -e /bin/sh -c "ls -la /"
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$ ntctty.exe --log-level=7 -e /bin/sh -c "ls -la /"
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```
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By default, ``ntctty.exe`` log files are written into the /var/log/ntctty
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directory; this may be adjusted with the ``--log-dir`` and/or
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``--log-file`` options. ``strace(1)`` logs to stderr by default.
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 3. Common concepts and tasks"
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## 3. Common concepts and tasks
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[//]: # "}}}"
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[//]: # "{{{ 3.1. Common tasks"
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### 3.1. Common tasks
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Rebuild set of packages in isolation:
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```shell
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./build.sh [ ... ] -r mc,zsh
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```
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Restart the ``@install`` (shorthand alias) step, with implicit ``finish``, of the
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``mc`` and ``zsh`` packages.
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```shell
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./build.sh [ ... ] -r mc,zsh:@install
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```
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Rebuild set of packages along w/ their dependencies, if any, as needed, or forcibly,
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respectively:
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```shell
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./build.sh [ ... ] -r \*mc,zsh
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./build.sh [ ... ] -r \*\*mc,zsh
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```
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Forcibly rebuild all reverse dependencies of a set of packages:
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```shell
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./build.sh [ ... ] -r \*\*\*glib,libflac
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```
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Restart the ``@configure``, ``@build``, and ``@install`` (shorthand alias) steps of the
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``coreutils`` package:
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```shell
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./build.sh -r coreutils:@configure,@build,@install
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```
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Rebuild entire build groups including or excluding group dependencies, respectively:
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```shell
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./build.sh [ ... ] -r ALL native_runtime
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./build.sh [ ... ] -r ALL =native_runtime
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```
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Forcibly (re)download all archive files and/or Git repositories associated with all packages:
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```shell
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./build.sh [ ... ] -r ALL:@fetch,finish
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```
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> N.B. the "finish" (pseudo-)build step must be included here and in similar use cases so that all
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affected packages are marked as having finished building in order to correctly satisfy package-package
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dependencies.
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 3.2. Adding a package"
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## 3.2. Adding a package
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Packages are grouped into *build groups* according to sets of common package
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variable defaults, such as ``${PKG_CFLAGS_CONFIGURE}, ${PKG_LDFLAGS_CONFIGURE}``
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and ``${PKG_CONFIGURE_ARGS}``, and semantic interrelatedness, such as the
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``native_runtime`` build group comprising the Midipix runtime components.
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Packages may belong to more than one build group such as when subsumed by a shorthand
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build group e.g. the ``dev_packages`` build group, as long as the default set of build
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groups or as overriden on the command line does not entail group membership conflicts.  
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Build groups files beneath ``groups.d/`` named ``[0-9][0-9][0-9].<group name>.group``
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contain package variable defaults, optionally the alphabetically sorted list of contained
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packages, if any, in ``<upper case group name>_PACKAGES``, and their package variables
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sorted alphabetically with the exception of ``${PKG_DEPENDS}`` (if present,)
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``${PKG_SHA256SUM}``, ``${PKG_URL}``, and ``${PKG_VERSION}``, and/or ``${PKG_URLS_GIT}``,
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which are specified in this order. Build group files require the following epilogue, the
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parameters enclosed in square brackets being optional:
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```shell
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ex_pkg_register_group "<group name>" "${RTL_FILEOP_SOURCE_FNAME}" [["owner|copy"] ["auto|noauto"]];
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# vim:filetype=sh textwidth=0
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```
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If ``copy`` is specified, the build group will copy all of its packages from their respective
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build groups without taking ownership thereof, if ``owner`` is specified, the default, the build
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group owns all of its packages. If ``noauto`` is specified, the build group will not be added to
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the list of build groups to build by default, if ``auto`` is specified, the build group will be
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added to the list of build groups to build by default.  
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If a build group that specifies ``copy`` should copy all of its build group variables from another
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build group, use the following code:
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```shell
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ex_pkg_copy_group_vars "<source group name>" "<destination group name>";
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```
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Additionally, single package files may be added beneath ``groups.d/[0-9][0-9][0-9].<group name>.d/``,
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named ``<package name>.package`` containing the package's variables, with the following epilogue,
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the parameters enclosed in square brackets being optional:
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```shell
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ex_pkg_register "<package_name>" "${RTL_FILEOP_SOURCE_FNAME}" ["<group name>"];
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# vim:filetype=sh textwidth=0
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```
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1. Pick a build group according to the criteria mentioned and specifiy the set of package
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variables required (see above and section [4.4](#44-package-variables)) in either the
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corresponding group file or a single package file; in the former case, do also add the
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package to the build group's list of contained packages.
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2. Consult section [3.5](#35-patches-and-vars-files) if the package to be added
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requires patches or additional code amending or replacing package build steps
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or the entire package build. Consult section [4.1](#41-build-steps) for a list
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of package build steps and how they are overriden.
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 3.3. Addressing build failure"
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## 3.3. Addressing build failure
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During package build, standard error and output are redirected into a log file beneath
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``${BUILD_WORKDIR}`` named ``${PKG_NAME}_stderrout.log``, following a package variable
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dump. If ``-V build`` was specified, package logs will additionally be printed to standard
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output. If ``-V xtrace`` was specified, ``xtrace`` will be set during package builds for
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rudimentary debugging purposes. Additionally, packages using GNU autotools will, if
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package configuration failed or appears relevant, log the configuration process in detail
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in, most usually, ``${PKG_BUILD_DIR}/config.log``.  
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 3.4. Package archive files and Git repositories"
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### 3.4. Package archive files and Git repositories
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Packages may have either or both of a SHA-256 message digest checked and to be extracted tarball
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(set in ``${PKG_URL}``, ``${PKG_FNAME}``, and ``${PKG_SHA256SUM}``) and/or Git repository or set
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thereof (set in ``${PKG_URLS_GIT}``.) Complementing these, an implicitly inferred or, in the
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presence of both, explicit primary source directory is specified for each package in ``${PKG_SUBDIR}``.
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Furthermore, these may be subject to download caching and/or setting up as well as maintaining
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mirrors, including automatic cleanup as well as deduplication in both cases.  
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A list of pertinent package variables and their formats follows:  
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| Name           | Format                                          |
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| -------------- | ----------------------------------------------- |
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| PKG_FNAME      | ``<single file name>``                          |
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| PKG_SHA256SUM  | ``<SHA-256 message digest>``                    |
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| PKG_SUBDIR     | ``<relative or single directory name>``         |
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| PKG_URL        | ``scheme:[//authority]path[?query][#fragment]`` |
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| PKG_URLS_GIT   | ``[subdir=]URL[@branch]``                       |
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 3.5. Patches and ``vars`` files"
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## 3.5. Patches and ``vars`` files
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Package patches are applied prior and/or subsequent to (GNU autotools or similar) package
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configuration during the ``configure_patch_pre`` and/or ``configure_patch`` build steps,
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respectively (see section [4.1](#41-build-steps).) Patch files are searched for beneath
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``patches/`` with the following globs and in-order:
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* ``${PKG_NAME}-${PKG_VERSION}_pre.local.patch``
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  or ``${PKG_NAME}_pre.local.patch`` (for packages lacking ``${PKG_VERSION}``)
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* ``${PKG_NAME}-${PKG_VERSION}_pre.local@${BUILD_HNAME}.patch``
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  or ``${PKG_NAME}_pre.local@${BUILD_HNAME}.patch`` (for packages lacking ``${PKG_VERSION}``)
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* ``${PKG_NAME}/*.patch``
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* ``${PKG_NAME}-${PKG_VERSION}.local.patch``
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  or ``${PKG_NAME}.local.patch`` (for packages lacking ``${PKG_VERSION}``)
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* ``${PKG_NAME}-${PKG_VERSION}.local@${BUILD_HNAME}.patch``
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  or ``${PKG_NAME}.local@${BUILD_HNAME}.patch`` (for packages lacking ``${PKG_VERSION}``)
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* ``${PKG_PATCHES_EXTRA}`` (if set)
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If the default set of package build steps does not suffice, such as if additional commands
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must be executed after package configuration or prior to building, or if an entire or all
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build step must be replaced, overrides may be specified in the form of functions in the
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package's ``vars/${PKG_NAME}.vars`` as well as ``vars.<group name>/${PKG_NAME}.vars``
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``vars`` file(s). Consult section [4.1](#41-build-steps) for a list of package build steps
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and how they are overriden.
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 4. Reference"
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## 4. Reference
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[//]: # "}}}"
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[//]: # "{{{ 4.1. Build steps"
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## 4.1. Build steps
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Package builds are divided up into consecutively executed build steps until
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completion or aborted on failure unless relaxed mode is enabled by passing
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``-R``.  
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Each build step corresponds to a function in the corresponding ``subr/pkg_*.subr``
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script and may be overriden entirely by a function named ``pkg_<package name>_<build step>()``
fe49bc
or composed in terms of prior and/or subsequent execution by a function named
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``pkg_<package name>_<build step>_pre()`` and/or ``pkg_<package name>_<build step>_post()``,
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respectively, in the package's ``vars`` file. If a function named ``pkg_<package name>_all()``
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exists, it will override all build steps.  
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Build step functions receive the following arguments in the order specified:
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| Name          | Description                                              |
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| ------------- | -------------------------------------------------------- |
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| \_group\_name | Package name                                             |
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| \_pkg\_name   | Group name                                               |
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| \_restart\_at | Optional list of build steps to restart package build at |
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Build step status is tracked on a per-package basis by state files beneath
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``${BUILD_WORKDIR}`` following the format ``.<package name>.<build step>``;
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package build completion corresponds to the pseudo-build step ``finish``.
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| Name                | Description                                                                                                                                                                                                                                              |
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| ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
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| fetch_clean         | Delete and create ``${PKG_SUBDIR}``                                                                                                                                                                                                                      |
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| fetch_download      | Download package archive & verify w/ SHA-256 message digest and/or clone Git repository/ies                                                                                                                                                              |
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| fetch_extract       | Extract package archive, if any                                                                                                                                                                                                                          |
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| configure_clean     | Delete and create ``${PKG_BUILD_DIR}``                                                                                                                                                                                                                   |
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| configure_patch_pre | Apply ``chainport`` patches and/or patches beneath ``patches/`` prior to (GNU autotools or similar) configuration                                                                                                                                        |
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| configure_autotools | Bootstrap (GNU autools or similar) environment, and install ``config.sub`` and ``config.cache``                                                                                                                                                          |
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| configure_patch     | Apply patches beneath ``patches/`` and/or set in ``${PKG_PATCHES_EXTRA}`` after (GNU autotools or similar) configuration                                                                                                                                 |
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| configure           | Perform package (GNU autools or similar or CMake) configuration w/ configuration-time set of environment variables                                                                                                                                       |
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| build_clean         | Clean ``${PKG_BUILD_DIR}`` w/ ``make clean`` invocation                                                                                                                                                                                                  |
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| build               | Call ``make(1)`` w/ build-time set of make variables                                                                                                                                                                                                     |
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| install_clean       | Delete and create ``${PKG_DESTDIR}``                                                                                                                                                                                                                     |
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| install_subdirs     | Create default directory hierarchy in ``${PKG_DESTDIR}``, optionally amended w/ ``${PKG_INSTALL_FILES_DESTDIR_EXTRA}``                                                                                                                                   |
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| install_make        | Call ``make(1)`` w/ ``${PKG_INSTALL_TARGET}`` (defaults to ``install``) and installation-time set of make variables                                                                                                                                      |
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| install_files       | Install ``${PKG_INSTALL_FILES}`` and/or ``${PKG_INSTALL_FILES_V2}``, fix directory and file mode bits within ``${PKG_DESTDIR}`` and optionally ``${PKG_DESTDIR_HOST}``, ``pkgconf(1)`` package files, and/or stripped binaries within ``${PKG_DESTDIR}`` |
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|                     | Purge libtool ``.la`` files and install shared objects within ``${PKG_DESTDIR}`` w/ ``perk`` and corresponding symbolic links                                                                                                                            |
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| install             | Install into ``${PKG_PREFIX}``, and optionally ``${PKG_DESTDIR_HOST}`` into ``${PREFIX}``, under mutex, and add package to ``${PREFIX}/pkglist.${PKG_BUILD_TYPE}`` (unless inhibited)                                                                    |
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| install_rpm         | Build package RPM w/ auto-generated specifiation file based on ``etc/package.spec`` beneath ``${PREFIX_RPM}``                                                                                                                                            |
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| clean               | Clean ``${PKG_BUILD_DIR}`` and/or ``${PKG_DESTDIR}`` and/or ``${PKG_DESTDIR_HOST}`` and/or ``${PKG_BASE_DIR}/${PKG_SUBDIR}`` as per ``-C build,dest,src``, resp., if any                                                                                 |
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 4.2. Build variables"
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## 4.2. Build variables
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The following variables are primarily defined in ``vars.env.d/*.env`` and may be
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overriden on a per-build basis on the command-line, the environment, and/or
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``${HOME}/midipix_build.vars``, ``${HOME}/.midipix_build.vars``, and/or
fe49bc
``../midipix_build.vars``, e.g.:
fe49bc
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```shell
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./build.sh -a nt64 -b release -D minipix,zipdist -P -v PREFIX_ROOT="${HOME}/midipix_tmp"
fe49bc
env ARCH=nt64 BUILD_KIND=release PREFIX_ROOT="${HOME}/midipix_tmp" ./build.sh -D minipix,zipdist -P -v
fe49bc
```
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| Variable name    | Default value                        | Description                                                                   |
fe49bc
| ---------------- | ------------------------------------ | ----------------------------------------------------------------------------- |
fe49bc
| ARCH             | nt64                                 | Target 32-bit (nt32) or 64-bit (nt64) architecture                            |
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| BUILD_DLCACHEDIR | ${PREFIX_ROOT}/dlcache               | Absolute pathname to package downloads cache root directory                   |
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| BUILD_HNAME      | $(hostname)                          | Build system hostname                                                         |
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| BUILD_KIND       | debug                                | Build w/ debugging (debug) or release compiler flags                          |
308fa7
| PREFIX_LOCAL     | ${PREFIX}/localcross                 | Absolute pathname to local cross-toolchain root directory                     |
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| BUILD_WORKDIR    | ${PREFIX}/tmp                        | Absolute pathname to temporary package build root directory                   |
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| PREFIX           | ${PREFIX_ROOT}/${ARCH}/${BUILD_KIND} | Absolute pathname to architecture- & build type-specific build root directory |
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| PREFIX_CROSS     | ${PREFIX}/${DEFAULT_TARGET}          | Absolute pathname to toolchain root directory                                 |
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| PREFIX_MINGW32   | ${PREFIX}/x86_64-w64-mingw32         | Absolute pathname to MinGW toolchain root directory                           |
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| PREFIX_MINIPIX   | ${PREFIX}/minipix                    | Absolute pathname to minipix distribution root directory                      |
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| PREFIX_NATIVE    | ${PREFIX}/native                     | Absolute pathname to cross-compiled packages root directory                   |
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| PREFIX_ROOT      | ${HOME}/midipix                      | Absolute pathname to top-level directory                                      |
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| PREFIX_RPM       | ${PREFIX}/rpm                        | Absolute pathname to package RPM archive root directory                       |
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 4.3. File installation DSL"
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## 4.3. File installation DSL
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File and directory installation, comprising e.g. copying, moving, creating
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symbolic links, setting owner and/or permission metadata, are expressed in
fe49bc
a descriptive domain-specific language and integrated with package building
fe49bc
via the package variable ``${PKG_INSTALL_FILES_V2}``, applying during
fe49bc
``install_files`` after the ``install_make`` build step, and ``${PKG_INSTALL_FILES_DESTDIR}``
fe49bc
and ``${PKG_INSTALL_FILES_DESTDIR_EXTRA}`` during ``install_subdirs``. The
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``${PKG_INSTALL_FILES_V2}`` must adhere to the following syntax specified in EBNF:  
fe49bc
fe49bc
```
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(*
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SH_GLOB_PATTERN      = any valid portable shell pattern (see sh(1)); superset of PATHNAME
fe49bc
SH_SUBSTRING_PATTERN = any valid portable substring processing shell pattern (see sh(1));
fe49bc
                       superset of PATHNAME
fe49bc
PARAMETER            = any valid portable shell variable name except that [0-9] may occur
fe49bc
                       the beginning
fe49bc
PATHNAME             = any valid filename, directory name, relative or absolute pathname
fe49bc
                       excluding the characters NUL and NL
fe49bc
 *)
fe49bc
fe49bc
spec                 = { op_flag, } op_unary, "=", op_spec, "\n", { spec } ;
fe49bc
                     | { op_flag, } op_binary, op_spec, "=" op_spec, "\n", { spec } ;
fe49bc
                     | "#" COMMENT ;
fe49bc
op_unary             = "-" | "/" | "t" ;
fe49bc
op_binary            = ":" | "!" | "@" | "+" | "g" | "m" | "o" | "T" ;
fe49bc
op_flag              = "?" ;
fe49bc
op_spec              = pattern_spec | PATHNAME | expr_spec | op_spec ;
fe49bc
fe49bc
pattern_spec         = "%<", SH_GLOB_PATTERN, ">" ;
fe49bc
fe49bc
expr_spec            = "%[", expr, { sexpr_spec }, "%]" ;
fe49bc
expr                 = [ "@" ], "0" .. "9" | "DNAME" | "FNAME" | "ITEM" | PARAMETER ;
fe49bc
fe49bc
sexpr_spec           = sexpr_op_unary, SH_SUBSTRING_PATTERN, { sexpr } ;
fe49bc
sexpr_op_unary       = "##" | "#" | "%%" | "%" ;
fe49bc
```
fe49bc
  
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Single ``"="`` characters in ``spec``, the ``"%<"`` and ``"%["`` character
fe49bc
sequences in ``pattern_spec`` and ``expr_spec``, resp., and the ``sexpr_op_unary``
fe49bc
as well as ``sexpr_op_binary`` characters or character sequences may be
fe49bc
escaped with a single backslash (``"\"``.) ``SH_SUBSTRING_PATTERN`` differs
fe49bc
from ``SH_GLOB_PATTERN`` solely in that any of ``sexpr_op_unary`` and
fe49bc
``sexpr_op_binary`` occuring at the beginning of or in the former must
fe49bc
be escaped with a single backslash (``"\"``,) e.g. ``"#\#pattern"`` and
fe49bc
``"%\%pattern"``, etc. and ``"#pat\%ern"`` and ``%patt\#ern", etc., resp.  
fe49bc
  
fe49bc
Named parameters (``PARAMETER``) are supplied via the ``-p name=value``
fe49bc
argument to ``rtl_install()``, whereas numbered parameters are for
fe49bc
internal usage only; the ``"DNAME"``, ``"FNAME"``, and ``"ITEM"`` parameters
fe49bc
lazily evaluate to the directory name, file (aka base) name, and full
fe49bc
pathname of the current item being processed relative to a specification
fe49bc
with a pattern in it.
fe49bc
  
fe49bc
The following parameters are defined by default during ``install_files``:
fe49bc
fe49bc
| Name           | Value                                  |
fe49bc
| -------------  | -------------------------------------- |
fe49bc
| _builddir      | ${PKG_BUILD_DIR}                       |
fe49bc
| _destdir       | ${PKG_BASE_DIR}/${PKG_DESTDIR}         |
fe49bc
| _destdir_host  | ${PKG_BASE_DIR}/${PKG_DESTDIR_HOST}    |
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| _files         | ${MIDIPIX_BUILD_PWD}/files/${PKG_NAME} |
fe49bc
| _name          | ${PKG_NAME}                            |
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| _prefix        | ${PKG_PREFIX}                          |
fe49bc
| _prefix_host   | ${PREFIX}                              |
fe49bc
| _prefix_native | ${PREFIX_NATIVE}                       |
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| _subdir        | ${PKG_BASE_DIR}/${PKG_SUBDIR}          |
fe49bc
| _target        | ${PKG_TARGET}                          |
fe49bc
| _version       | ${PKG_VERSION:-}                       |
fe49bc
| _workdir       | ${BUILD_WORKDIR}                       |
fe49bc
  
fe49bc
The following operation flags are defined:
fe49bc
fe49bc
| Flag      | Description              |
fe49bc
| --------- | ------------------------ |
fe49bc
| ``?``     | Continue on soft failure |
fe49bc
  
fe49bc
The following operations are defined:
fe49bc
fe49bc
| Operation      | Arity  | Description                                                      |
fe49bc
| -------------- | ------ | ---------------------------------------------------------------- |
fe49bc
| ``-``          | Unary  | Remove directories and/or files                                  |
fe49bc
| ``/``          | Unary  | Create directories or trees thereof                              |
fe49bc
| ``t``          | Unary  | touch(1) files and/or directories                                |
fe49bc
| ``:``          | Binary | Copy directories and/or files                                    |
fe49bc
| ``!``          | Binary | Move/rename directories and/or files                             |
fe49bc
| ``@``          | Binary | Create/update symbolic links                                     |
fe49bc
| ``+``          | Binary | Copy directories and/or files if newer and follow symbolic links |
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| ``g``          | Binary | Set group owner of files and/or directories                      |
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| ``m``          | Binary | Set mode bits of files and/or directories                        |
fe49bc
| ``o``          | Binary | Set user and/or group owner of files and/or directories          |
fe49bc
| ``T``          | Binary | touch(1) files and/or directories with timestamp                 |
fe49bc
  
fe49bc
The following expression modifiers are defined:
fe49bc
fe49bc
| Modifier       | Description                               |
fe49bc
| -------------- | ----------------------------------------- |
fe49bc
| ``@``          | Recursively reevaluate after substituting |
fe49bc
  
fe49bc
The following subexpression operators are defined:
fe49bc
fe49bc
| Operation      | Arity  | Description                                                      |
fe49bc
| -------------- | ------ | ---------------------------------------------------------------- |
fe49bc
| ``##``         | Unary  | Remove largest prefix from left-hand side                        |
fe49bc
| ``#``          | Unary  | Remove prefix from left-hand side                                |
fe49bc
| ``%%``         | Unary  | Remove largest postfix from right-hand side                      |
fe49bc
| ``%``          | Unary  | Remove postfix from right-hand side                              |
fe49bc
  
fe49bc
```shell
fe49bc
#
fe49bc
# Examples:
fe49bc
# 
fe49bc
fe49bc
#
fe49bc
# Create directory %[_minipix]/bin and copy all files
fe49bc
# in %[_minipix_dist]/bin/ to %[_minipix]/bin/ with
fe49bc
# identical file names.
fe49bc
/=%[_minipix]/bin
fe49bc
?%[_minipix_dist]/bin/%<*>=%[_minipix]/bin/%[FNAME]
fe49bc
fe49bc
#
fe49bc
# Rename all files in share/info/ matching *.info to
fe49bc
# their filenames with the `.info' postfix removed and
fe49bc
# `-2.64.info' appended and all files in share/man/man1/
fe49bc
# matching *.1 with the `.1' postfix removed and -2.64.1
fe49bc
# appended.
fe49bc
!share/info/%<*.info>=share/info/%[FNAME%.info]-2.64.info
fe49bc
!share/man/man1/%<*.1>=share/man/man1/%[FNAME%.1]-2.64.1
fe49bc
fe49bc
#
fe49bc
# Create/update symbolic links named include/ffi.h and
fe49bc
# include/ffitarget.h with ../lib/libffi-3.2.1/include/ffi.h
fe49bc
# and ../lib/libffi-3.2.1/include/ffitarget.h as targets, resp.
fe49bc
@../lib/libffi-3.2.1/include/ffi.h=include/ffi.h
fe49bc
@../lib/libffi-3.2.1/include/ffitarget.h=include/ffitarget.h
fe49bc
fe49bc
#
fe49bc
# Manual invocation:
fe49bc
PKG_INSTALL_FILES_V2="
fe49bc
        [ ... ]
fe49bc
";
fe49bc
rtl_install                                                     \
fe49bc
                -p "_builddir=${PKG_BASE_DIR}/${PKG_BUILD_DIR}" \
fe49bc
                -p "_minipix=${PREFIX_MINIPIX##*/}"             \
fe49bc
                -p "_minipix_dist=${PREFIX}/minipix_dist"       \
fe49bc
                -p "_native=${PREFIX_NATIVE##*/}"               \
fe49bc
                -p "_subdir=${PKG_BASE_DIR}/${PKG_SUBDIR}"      \
fe49bc
                -p "_target=${PKG_TARGET}"                      \
fe49bc
                -n -- "${PREFIX}"                               \
fe49bc
                "${PKG_INSTALL_FILES_V2}"; then
fe49bc
        return 1;
fe49bc
fi;
fe49bc
fe49bc
#
fe49bc
# Usage screen:
fe49bc
usage: rtl_install [-i] [-I ifs] [-n] [-p name=val] [-v] prefix spec_list
fe49bc
       -i...........: continue on soft errors
fe49bc
       -I ifs.......: process spec_list with ifs instead of NL
fe49bc
       -n...........: perform dry run
fe49bc
       -p name=val..: set named parameter
fe49bc
       -v...........: increase verbosity
fe49bc
       prefix.......: pathname prefix
fe49bc
       spec_list....: ifs-separated list of specs
fe49bc
```
fe49bc
  
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[Back to top](#table-of-contents)
fe49bc
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[//]: # "}}}"
fe49bc
[//]: # "{{{ 4.4. Package variables"
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### 4.4. Package variables
fe49bc
fe49bc
The following variables are package-specific and receive their value from either
fe49bc
top-level defaults defined in ``vars.env.d/*.env``, build group-specific defaults from the
fe49bc
build group the package pertains to and defined in its corresponding file beneath
931865
``groups.d/`` or ``groups.d/[0-9][0-9][0-9].<group name>.d/``, or package-specific overrides
931865
defined either in the latter and/or in its corresponding file beneath ``vars/``, with one of
931865
the following prefixes:
fe49bc
fe49bc
| Variable name prefix                              |
fe49bc
| ------------------------------------------------- |
fe49bc
| DEFAULT                                           |
fe49bc
| DEFAULT_``${BUILD_TYPE}``                         |
fe49bc
| DEFAULT_``${GROUP_NAME}``                         |
fe49bc
| ``${GROUP_NAME}``                                 |
fe49bc
| [PKG_``${RELATED_PACKAGE(S)}``]                   |
fe49bc
| [PKG_``${RELATED_PACKAGE(S)}``_``${BUILD_KIND}``] |
fe49bc
| PKG_``${NAME}``                                   |
fe49bc
| PKG_``${NAME}``_``${BUILD_KIND}``                 |
fe49bc
fe49bc
Additionally, overrides may be specified on a per-build basis on the command-
fe49bc
line, with each variable prefixed w/ ``PKG_``, e.g.:
fe49bc
``./build.sh [ ... ] PKG_ZSH_CC="/usr/bin/clang"``.  
fe49bc
  
fe49bc
The minimum set of package variables that must be provided is ``SHA256SUM, URL,
fe49bc
VERSION`` and/or ``URLS_GIT``, respectively.
fe49bc
fe49bc
[//]: # "{{{ 4.4.1 Package variable types"
fe49bc
## 4.4.1 Package variable types
fe49bc
fe49bc
| Type definition               | Description                                                                                                                                  |
fe49bc
| ----------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
fe49bc
| DirName(Abs)			| Absolute pathname to directory                                                                                                               |
fe49bc
| DirName(Rel)			| Relative pathname to director                                                                                                                |
fe49bc
| DirName(Unit)			| Single non-{absolute,relative} directory nam                                                                                                 |
fe49bc
| DirName			| Absolute or relative pathname to director                                                                                                    |
fe49bc
| CmdName			| Absolute or relative pathname to comman                                                                                                      |
fe49bc
| FileName(Abs)			| Absolute pathname to file                                                                                                                    |
fe49bc
| FileName(Rel)			| Relative pathname to file                                                                                                                    |
fe49bc
| FileName(Unit)		| Single non-{absolute,relative} file name                                                                                                     |
fe49bc
| FileName			| Absolute or relative pathname to file                                                                                                        |
fe49bc
| Flag(<type>,<default>)	| Boolean flag of type <type>, e.g. Flag(Boolean) (``true``, ``false``,) Flag(UInt) (0, 1,) Flag(ExitStatus) (>=1, 0) with default or ``auto`` |
fe49bc
| FlagLine			| String of {SP,VT}-separated flags, arguments, options, etc. pp. to a command                                                                 |
fe49bc
| List(<sep>[,<sep\|type>..])	| \<sep\>-separated list, optionally recursively and/or sub-typing, e.g.: ``List(:,=,String)`` and ``"name=value:name2=value"``                |
fe49bc
| PkgName			| Single name of package                                                                                                                       |
fe49bc
| PkgRelation			| Single, possibly parametrised, package-package relation; see section [3.5](#35-package-package-and-packagegroup-group-relationships)         |
fe49bc
| PkgVersion			| Single version of package                                                                                                                    |
fe49bc
| Set(<type>)			| Set of alternatives of <type>, e.g. one of ``cross``, ``host``, ``native``                                                                   |
fe49bc
| String			| Semantically generic string                                                                                                                  |
fe49bc
| URL				| URL in standard format; see section [3.4](#34-package-archive-files-and-git-repositories)                                                    |
fe49bc
| URL(Git)			| Git URL in the format ``[subdir=]URL[@branch]``; see section [3.4](#34-package-archive-files-and-git-repositories)                           |
fe49bc
fe49bc
[//]: # "}}}"
fe49bc
[//]: # "{{{ 4.4.2 Package variables"
fe49bc
## 4.4.2 Package variables
fe49bc
fe49bc
| Package variable name        | Type             | Description                                                                                                                                |
fe49bc
| ---------------------------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------ |
fe49bc
| AR                           | CmdName          | Toolchain library archive editor ``ar(1)``                                                                                                 |
fe49bc
| AUTOCONF_CONFIG_GUESS        | String           | Either of ``copy`` (copy ``config.guess`` from ``etc/config.guess``) or ``keep``; defaults to ``copy``                                     |
fe49bc
| BASE_DIR                     | DirName(Abs)     | Package build root directory beneath ``${BUILD_WORKDIR}``                                                                                  |
fe49bc
| BUILD_DIR                    | DirName(Unit)    | Package build directory beneath ``${PKG_BASE_DIR}``                                                                                        |
a88b49
| BUILD_STEPS_DISABLE          | List( )          | Build steps to disable during package build                                                                                                |
fe49bc
| BUILD_TYPE                   | Set(String)      | ``cross``: Cross-compiled toolchain, ``host``: host, ``native``: cross-compiled package                                                    |
fe49bc
| CC                           | FileName         | Toolchain C compiler ``cc(1)``                                                                                                             |
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| CCLD                         | FileName         | Toolchain C compiler-qua-linker ``cc(1)``                                                                                                  |
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| CFLAGS_BUILD_EXTRA           | FlagLine         | Additional C compiler flags during package ``make(1)`` build                                                                               |
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| CFLAGS_BUILD                 | FlagLine         | C compiler flags during package ``make(1)``  build                                                                                         |
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| CFLAGS_CONFIGURE_EXTRA       | FlagLine         | Additional C compiler flags during package (GNU autotools in implementation and/or interface) configuration                                |
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| CFLAGS_CONFIGURE             | FlagLine         | C compiler flags during package (GNU autotools in implementation and/or interface) configuration                                           |
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| CMAKE_ARGS_EXTRA             | FlagLine         | Additional arguments to ``cmake(1)``                                                                                                       |
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| CMAKE_ARGS                   | FlagLine         | Arguments to ``cmake(1)``                                                                                                                  |
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| CMAKE                        | CmdName          | ``cmake(1)`` executable                                                                                                                    |
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| CMAKE_LISTFILE               | FileName         | ``cmake(1)`` listfile                                                                                                                      |
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| CONFIG_CACHE_EXTRA           | List(\n)         | Additional GNU autotools configuration cache variables                                                                                     |
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| CONFIG_CACHE                 | List(\n)         | GNU autotools configuration cache variables                                                                                                |
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| CONFIG_CACHE_LOCAL           | List(\n)         | Additional GNU autotools configuration cache variables                                                                                     |
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| CONFIGURE_ARGS               | FlagLine         | Arguments to package (GNU autotools in implementation and/or interface) configuration script                                               |
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| CONFIGURE_ARGS_EXTRA         | FlagLine         | Additional arguments to package (GNU autotools in implementation and/or interface) configuration script                                    |
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| CONFIGURE_ARGS_LIST          | List(:)          | Arguments to package (GNU autotools in implementation and/or interface) configuration script                                               |
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| CONFIGURE_ARGS_EXTRA_LIST    | List(:)          | Additional arguments to package (GNU autotools in implementation and/or interface) configuration script                                    |
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| CONFIGURE                    | CmdName          | Package's (GNU autotools in implementation and/or interface) configuration script                                                          |
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| CONFIGURE_TYPE               | String           | Either of ``autotools`` (GNU autotools or similar) or ``sofort`` or ``cmake`` (CMake)                                                      |
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| CPPFLAGS_CONFIGURE_EXTRA     | FlagLine         | Additional C preprocessor flags during package (GNU autotools in implementation and/or interface) configuration                            |
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| CXX                          | CmdName          | Toolchain C++ compiler ``c++(1)``                                                                                                          |
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| CXXFLAGS_CONFIGURE_EXTRA     | FlagLine         | Additional C++ compiler flags during package (GNU autotools in implementation and/or interface) configuration                              |
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| CXXFLAGS_CONFIGURE           | FlagLine         | C++ compiler flags during package (GNU autotools in implementation and/or interface) configuration                                         |
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| DEPENDS                      | List( )          | Mandatory package-package dependencies                                                                                                     |
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| DESTDIR                      | DirName(Unit)    | Package installation destination directory beneath ``${PKG_BASE_DIR}``                                                                     |
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| DESTDIR_HOST                 | DirName(Unit)    | Optional host package installation destination directory beneath ``${PKG_BASE_DIR}``                                                       |
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| DISABLED                     | Flag(UInt,0)     | Disable package                                                                                                                            |
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| ENV_VARS_EXTRA               | List(:,=)        | Name-value pairs of environment variables to set during package build                                                                      |
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| FNAME                        | FileName(Unit)   | Filename of package archive file                                                                                                           |
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| FORCE_AUTORECONF             | Flag(UInt,0)     | Forcibly run ``autoreconf -fiv`` prior to package (GNU autotools in implementation and/or interface) configuration                         |
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| GITROOT                      | URL              | midipix packages Git URL prefix                                                                                                            |
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| INHERIT_FROM                 | String           | Inherit variables from named package                                                                                                       |
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| INSTALL_FILES_DESTDIR_EXTRA  | List( )          | Additional files to initialise the package installation destination directory beneath ``${PKG_BASE_DIR}`` with                             |
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| INSTALL_FILES_DESTDIR        | List( )          | Files to initialise the package installation destination directory beneath ``${PKG_BASE_DIR}`` with                                        |
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| INSTALL_FILES                | List( )          | Files to manually install into the package installation destination directory beneath ``${PKG_BASE_DIR}``                                  |
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| INSTALL_FILES_V2             | List( )          | Files to manually install into the package installation destination directory beneath ``${PKG_BASE_DIR}``                                  |
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| INSTALL_TARGET_EXTRA         | String           | Additional name of package build ``make(1)`` installation target                                                                           |
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| INSTALL_TARGET               | String           | Name of package build ``make(1)`` installation target                                                                                      |
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| IN_TREE                      | Flag(UInt,auto)  | Build package in-tree within ``${PKG_SUBDIR}``                                                                                             |
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| LDFLAGS_BUILD_EXTRA          | FlagLine         | Additional linker flags during package ``make(1)``  build                                                                                  |
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| LDFLAGS_CONFIGURE_EXTRA      | FlagLine         | Additional linker flags during package (GNU autotools in implementation and/or interface) configuration                                    |
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| LDFLAGS_CONFIGURE            | FlagLine         | Linker flags during package (GNU autotools in implementation and/or interface) configuration                                               |
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| LIBTOOL                      | CmdName          | ``libtool(1)`` implementation (defaults to ``slibtool``)                                                                                   |
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| MAKE                         | CmdLine          | Command line of ``make(1)``                                                                                                                |
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| MAKEFLAGS_BUILD              | FlagLine         | ``make(1)`` flags during package ``make(1)``  build; subject to field splitting w/ ``:``                                                   |
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| MAKEFLAGS_BUILD_EXTRA        | FlagLine         | Additional ``make(1)`` flags during package ``make(1)``  build; subject to field splitting w/ ``:``                                        |
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| MAKEFLAGS_BUILD_LIST         | List(:)          | ``make(1)`` flags during package ``make(1)``  build; subject to field splitting w/ ``:``                                                   |
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| MAKEFLAGS_BUILD_EXTRA_LIST   | List(:)          | Additional ``make(1)`` flags during package ``make(1)``  build; subject to field splitting w/ ``:``                                        |
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| MAKEFLAGS_INSTALL            | FlagLine         | ``make(1)`` flags during package ``make(1)``  installation; subject to field splitting w/ ``:``                                            |
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| MAKEFLAGS_INSTALL_EXTRA      | FlagLine         | ``make(1)`` flags during package ``make(1)``  installation; subject to field splitting w/ ``:``                                            |
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| MAKEFLAGS_INSTALL_LIST       | List(:)          | ``make(1)`` flags during package ``make(1)``  installation; subject to field splitting w/ ``:``                                            |
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| MAKEFLAGS_INSTALL_EXTRA_LIST | List(:)          | ``make(1)`` flags during package ``make(1)``  installation; subject to field splitting w/ ``:``                                            |
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| MAKEFLAGS_LOADAVG            | FlagLine         | ``make(1)`` load average limit (e.g. -l load) flag                                                                                         |
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| MAKEFLAGS_PARALLELISE        | FlagLine         | ``make(1)`` parallelisation (e.g. -j jobs) flag                                                                                            |
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| MAKEFLAGS_VERBOSITY          | String           | Variable-value pair to pass to ``make(1)`` in order to force echo-back of command lines prior to execution                                 |
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| MAKE_INSTALL_VNAME           | String           | Variable name of ``make(1)`` installation destination directory variable during package ``make(1)``  installation                          |
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| MAKE_SUBDIRS                 | List( )          | ``make(1)`` subdirectories to exclusively build                                                                                            |
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| MIRRORS_GIT                  | List( )          | Package Git repository mirror base URLs to attempt cloning from; cf. ``pkgtool.sh -m <dname>``                                             |
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| MIRRORS                      | List( )          | Package archive mirror base URLs to attempt downloading from; cf. ``pkgtool.sh -m <dname>``                                                |
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| NO_CLEAN_BASE_DIR            | Flag(UInt,0)     | Inhibit cleaning of package build root directory beneath ``${BUILD_WORKDIR}``                                                              |
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| NO_CLEAN                     | Flag(UInt,0)     | Inhibit cleaning of package build directory beneath ``${PKG_BASE_DIR}`` pre-finish                                                         |
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| NO_LOG_VARS                  | Flag(UInt,0)     | Inhibit logging of build & package variables pre-package build                                                                             |
cb4e88
| NO_PURGE_LA_FILES            | Flag(UInt,0)     | Inhibit purging of .la files                                                                                                               |
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| PATCHES_EXTRA                | List( )          | Additional patches to apply                                                                                                                |
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| PKG_CONFIG                   | CmdName          | ``pkg-config(1)`` implementation                                                                                                           |
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| PKG_CONFIG_LIBDIR            | DirName          | ``pkg-config(1)`` search directory                                                                                                         |
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| PKGLIST_DISABLE              | Flag(UInt,0)     | Inhibit inclusion into ``${PREFIX}/pkglist.${PKG_BUILD_TYPE}``                                                                             |
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| PREFIX                       | DirName(Abs)     | Top-level installation directory and package search path                                                                                   |
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| PYTHON                       | CmdName          | Python >=3.x interpreter                                                                                                                   |
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| RANLIB                       | CmdName          | Toolchain library archive index generator ``ranlib(1)``                                                                                    |
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| RELATES                      | Set(PkgRelation) | Package-package relationships                                                                                                              |
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| RPM_DISABLE                  | Flag(UInt,0)     | Inhibit creation of RPM archive                                                                                                            |
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| SHA256SUM                    | String           | SHA-256 message digest of package archive                                                                                                  |
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| SOFORT_NATIVE_CC             | FileName         | ``sofort`` variable during ``native`` build: Toolchain C compiler ``cc(1)``                                                                |
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| SOFORT_NATIVE_CFLAGS_EXTRA   | FlagLine         | ``sofort`` variable during ``native`` build: Additional C compiler flags during package (GNU autotools or similar) configuration           |
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| SOFORT_NATIVE_CFLAGS         | FlagLine         | ``sofort`` variable during ``native`` build: C compiler flags during package (GNU autotools or similar) configuration                      |
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| SOFORT_NATIVE_CXXFLAGS_EXTRA | FlagLine         | ``sofort`` variable during ``native`` build: Additional list of C++ compiler flags during package (GNU autotools or similar) configuration |
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| SOFORT_NATIVE_CXXFLAGS       | FlagLine         | ``sofort`` variable during ``native`` build: List of C++ compiler flags during package (GNU autotools or similar) configuration            |
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| SOFORT_NATIVE_CXX            | FlagLine         | ``sofort`` variable during ``native`` build: Command- or pathname of toolchain C++ compiler ``c++(1)``                                     |
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| SOFORT_NATIVE_LDFLAGS_EXTRA  | FlagLine         | ``sofort`` variable during ``native`` build: Additional linker flags during package (GNU autotools or similar) configuration               |
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| SOFORT_NATIVE_LDFLAGS        | FlagLine         | ``sofort`` variable during ``native`` build: Linker flags during package (GNU autotools or similar) configuration                          |
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| SOFORT_NATIVE_LD             | FileName         | ``sofort`` variable during ``native`` build: Command- or pathname of toolchain C compiler ``cc(1)``                                        |
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| SUBDIR                       | DirName(Rel)     | Extracted archive or git-{clone,pull}(1)'d directory                                                                                       |
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| TARGET                       | String           | Dash-separated {build,host,target} triplet                                                                                                 |
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| URL                          | List( ,URL)      | URL to package archives w/ optional alternatives; see section [3.4](#34-package-archive-files-and-git-repositories)                        |
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| URLS_GIT                     | List( ,URL(Git)) | Package Git URL(s) (format: ``[subdir=]URL[@branch]``, see section [3.4](#34-package-archive-files-and-git-repositories))                  |
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| VARS_FILE                    | FileName         | Optional package variables file (defaults to ``vars/${PKG_NAME}.vars``)                                                                    |
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| VERSION                      | PkgVersion       | Package version                                                                                                                            |
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[//]: # "}}}"
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 4.5. Fault-tolerant & highly optimised 3D laser show-equipped usage screen"
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## 4.5. Fault-tolerant & highly optimised 3D laser show-equipped usage screen
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```
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usage: ./build.sh [-a nt32|nt64]  [-b debug|release]    [-C dir[,..]]  [-D kind[,..]]
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                  [-F ipv4|ipv6|offline]    [-h|--help] [-p jobs|-P]    [-r ALL|LAST]
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                  [-r [*[*[*]]]name[,..][:ALL|LAST|[^|<|<=|>|>=]step,..]]        [-R]
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                  [-v] [-V [+]tag|pat[,..]]
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                  [--as-needed] [--debug-minipix]  [--reset-state] [--roar]
cc579e
                  [--theme theme]
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                  [[=]<group[,..][ ..]>|<variable name>=<variable override>[ ..]]
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        -a nt32|nt64        Selects 32-bit or 64-bit architecture; defaults to nt64.
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        -b debug|release    Selects debug or release build kind; defaults to debug.
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        -C dir[,..]         Clean build directory (build,) ${PREFIX} before processing build
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                            scripts (prefix,) source directory (src,) and/or destination
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                            directory (dest) after successful package builds.
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        -D kind[,..]        Produce minimal midipix distribution directory (minipix,) RPM
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                            binary packages (rpm,) and/or deployable distribution ZIP
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                            archive (zipdist.) zipdist implies minipix.
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        -F ipv4|ipv6|offline
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                            Force IPv4 (ipv4) or IPv6 (ipv6) when downloading package
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                            archives and/or Git repositories or don't download either at all
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                            (offline.)
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        -h|--help           Show short/full help screen, respectively.
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        -p jobs|-P          Enables parallelisation at group-level, whenever applicable.
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                            The maximum count of jobs defaults to the number of logical
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                            processors on the host system divided by two (2.)
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                            If -R is not specified and at least one (1) package fails to
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                            build, all remaining package builds will be forcibly aborted.
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        -r ALL|LAST         Restart all packages or the last failed package and resume
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                            build, resp.
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        -r [*[*[*]]]name[,..][:ALL|LAST|[^|<|<=|>|>=]step,..]
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                            Restart the specified comma-separated package(s) w/ inhibition
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                            of package build step state resetting completely (`ALL',) starting
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                            at the resp. last successfully executed build steps (`LAST',) or the
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                            specified comma-separated list of build steps, optionally subject
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                            concerning package name(s) and/or build step(s) to the below modifiers:
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                            Prepend name w/ `*' to automatically include dependencies, `**'
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                            to forcibly rebuild all dependencies, and `***' to forcibly
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                            rebuild all packages that depend on the specified package(s).
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                            Prepend step w/ `^' to filter build steps with, `<' or `<='
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                            to constrain build steps to below or below or equal with, resp.,
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                            `>' or `>=' to constrain build steps to above or above or equal
fe49bc
                            with, resp.
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                            Currently defined build steps are:
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                            fetch_clean, fetch_download, fetch_extract, configure_clean,
fe49bc
                            configure_patch_pre, configure_autotools, configure_patch,
fe49bc
                            configure, build_clean, build, install_clean, install_subdirs,
cc579e
                            install_make, install_files, install, install_rpm,
cc579e
                            and clean.
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                            Additionally, the following virtual steps are provided:
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                            @fetch, @configure, @build, @install, @clean, and finish.
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        -R                  Ignore build failures, skip printing package logs, and continue
fe49bc
                            building (relaxed mode.)
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        -v                  Increase logging verbosity.
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        -V [+]tag|pat[,..]  Enable logging for messages with tag or pattern matching tags of:
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                            + (prefix)..: initialise tags with normal verbosity (implies normal) (see etc/build.theme,)
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                            all.........: log everything (see etc/build.theme,)
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                            clear|none..: log nothing,
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                            normal......: log at normal verbosity (see etc/build.theme,)
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                            verbose.....: log at increased verbosity (implies normal) (see etc/build.theme) (-v,)
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                            build.......: log package build logs,
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                            fileops.....: log RTL file operations,
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                            install.....: log RTL installation DSL operations,
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                            zipdist.....: log deployable distribution ZIP archive operations,
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                            xtrace......: set xtrace during package builds,
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                            fatal.......: fatal, unrecoverable errors,
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                            info........: informational messages,
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                            verbose.....: verbose informational messages,
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                            warning.....: warning messages possibly relating to imminent fatal, unrecoverable errors,
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                            build_*.....: general build messages (viz.: begin, finish, finish_time, vars,)
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                            group_*.....: build group messages (viz.: begin, finish,)
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                            pkg_*.......: package build messages (viz.: begin, finish, msg, skip, step, strip.)
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        --as-needed         Don't build unless the midipix_build repository has received
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                            new commits.
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        --debug-minipix     Don't strip(1) minipix binaries to facilitate debugging minipix.
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        --reset-state       Reset package build step state on exit.
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        --theme theme       Set theme.
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        <group>[,..][ ..]   One of: dev_packages, dist, host_deps, host_deps_rpm,
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                            host_toolchain, host_tools, minipix, native_packages,
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                            native_runtime, native_toolchain, native_tools.
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                            Prepend w/ `=' to inhibit group-group dependency expansion.
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        <variable name>=<variable override>[ ..]
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                            Override build or package variable.
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```
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 4.6. ``pkgtool.sh``"
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## 4.6. ``pkgtool.sh``
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```
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usage: ./pkgtool.sh [-a nt32|nt64] [-b debug|release] [-e|-f|-i|-m <dname> -M <dname>|-p|-r|-t]
fe49bc
                    [--theme theme] [-v]
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                    [<variable name>=<variable override>[ ..]] name[,name..]
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        -a nt32|nt64      Selects 32-bit or 64-bit architecture; defaults to nt64.
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        -b debug|release  Selects debug or release build kind; defaults to debug.
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        -e                Edit package group file of single named package with ${EDITOR}.
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        -f                List files installed by single package.
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        -i                List package variables and dependencies of named package(s).
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        -m <dname>        Setup package archives mirror in <dname> and/or
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        -M <dname>        Setup Git repositories mirror in <dname>
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                          Specify "" or '' as <dname> to default to the defaults in
fe49bc
                          ${HOME}/pkgtool.vars, if present.
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        -p <log_fname>    Profile last build.
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        -r                List recursive reverse dependencies of single named package.
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        -t                Produce tarball of package build root directory and build log
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                          file for the purpose of distribution given build failure.
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        -v                Increase verbosity.
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        <variable name>=<variable override>[ ..]
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                          Override build or package variable.
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```
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> N.B. When using ``pkgtool.sh`` on a build w/ build variables (see section [4.2](#42-build-variables))
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overriden on the command line or via the environment, ensure that they are included in the
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``pkgtool.sh`` command line, preceding the package name, or exported, respectively.  
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> N.B. ``pkgtool.sh`` will source the ``${HOME}/pkgtool.vars`` file, if present, on startup where the
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following option arguments may be set: ``-a nt32|nt64`` by setting ``ARCH=...``, ``-b debug|release``
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by setting ``BUILD_KIND=...``, ``-m <dname>`` by setting ``ARG_MIRROR_DNAME=...``, and ``-M <dname>``
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by setting ``ARG_MIRROR_DNAME_GIT=...``.  
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 4.7. Bourne shell coding rules"
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## 4.7. Bourne shell coding rules
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4e929d
> N.B. Input sanitisation is mandatory whenever input may form part of a parameter name, most usually
4e929d
when indexing with input as a key into a (pseudo-)hash, e.g. PKG_ZSH_<...input...>; failing to do so
4e929d
may introduce security vulnerabilities (e.g.: $(arbitrary_command) and ${arbitrary_variable} facilitating
4e929d
code execution and information disclosure, resp.)  
4e929d
Do not use this code and these coding rules if this is not possible or impractical.
4e929d
4e929d
*(reproduced from [[shrtl](https://github.com/lalbornoz/shrtl/blob/master/README.md)])*
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If no rationale is specified for any specific point, the rationale is avoidance of undefined behaviour
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and/or implicit behaviour contingent on often subtle special cases, both of which are prone to cause
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hard to debug or even diagnose bugs.
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### Shell options
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1)  The `noglob` option is set at all times *except* for when globbing is required, e.g.:
fe49bc
    `set +o noglob; files=*; set -o noglob`
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2)  The `nounset` option is set at all times; if a parameter is to be expanded that may be
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    unset, use the `${parameter:-word}` expansion format.
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3)  The `errexit` option is unset at all times *except* for top-level subshell code that does
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    *not* engage in conditional evaluation, e.g. `([...] set -o errexit; [...]) &` due to its
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    implicit unsetting when a/any function is subject to conditional evaluation, e.g.: `[...]
fe49bc
    set -o errexit; [...] if some_function; then [ ... ] fi`
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### Quoting and brace-enclosing
fe49bc
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4)  Quoting with single quotes or double quotes is mandatory at all times *except* for when field 
fe49bc
    splitting subsequent to parameter expansion, etc. is required, e.g.: `params="a b c";
fe49bc
    param="single parameter"; fn ${params} "${param}"`
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5)  Enclosing parameter names in braces is mandatory at all times, e.g.: `${parameter_name123}`
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### Checking parameter status
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6)  Checking for whether a parameter is set/non-empty or unset/empty is expressed with the following
fe49bc
    the idiom: `[ "${parameter:+1}" = 1 ]` and `[ "${parameter:+1}" != 1 ]` 
fe49bc
  
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    This is necessary to avoid the potentially costly expansion of a parameter's value when only its
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    status of being set/non-empty or unset/empty is of concern, particularly when this is done repeatedly.
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### Functions
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7)  Functions must explicitly return either `0` or `1` at all times *except* for when specific
fe49bc
    return exit statuses are specified according to the function's interface contract.
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8)  Function names must have namespace prefixes followed by a `p` in the topmost namespace prefix
fe49bc
    field in private functions, e.g.: `rtlp_log_do_something() { [...] }`
fe49bc
9)  The non-POSIX but extremely widely available `local` command must be used at at all times
fe49bc
    in functions on all function-local variables.  
fe49bc
  
fe49bc
    This is necessary in order to avoid polluting the (global) parameter namespace.
fe49bc
10) Function-local variables must be lower case and prefixed with a `_`, a prefix comprised of the
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    initial letters of each word in the function's name plus, in private functions, the `p` topmost
fe49bc
    namespace prefix field postfix, and a `_`, where words are separated by `_` characters, e.g.:
fe49bc
    `rtlp_log_do_something() { local _rplds_parameter=""; [...] }` and `ex_something() {
fe49bc
    local _es_parameter=""; [ ...] }` 
fe49bc
  
fe49bc
    This is necessary in order to prevent implicit conflicts between two or more functions that share
fe49bc
    a call path and would otherwise use the same variables names, such as `function1() { local
fe49bc
    list="${1}"; function2 "${list}"; }; function2() { local list="${2}"; }`, particularly when those
fe49bc
    functions acess and/or mutate each other's variables. Additionally, local variables are thus marked
fe49bc
    with a `_` prefix and by being lower case.
fe49bc
fe49bc
### `eval` rules
fe49bc
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11) The following special characters must be escaped with a backslash at all times in `eval`
fe49bc
    expressions: `<newline>`, `"`, `'`, `[`, `\`, `]`, `<backtick>`, `$`
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12) If parameter expansion is to be evaluated with respect to a parameter reference, the following idiom
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    must be used at all times: `eval [...]\${${rparameter[...]}}`
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13) If quoting with single quotes or double quotes is required - see 4) - or brace-enclosing - see 5) -
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    and with respect to 11), viz. the single quotes or double quotes have been escaped with a backslash,
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    something must be evaluated as a single field, then that field must be doubly quoted with single or
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    double quotes, where the second set of quotes must not be escaped with a backslash, e.g.: `
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    rparameter=parameter; eval ${rparameter}="\"a b c\""`. 
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    This is very rarely required.
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### Passing arguments
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14) The `fork/exec/write`-`read` pattern where a parameter is set to the result of a command
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    substitution expression which is executed in a subshell process, e.g.: `parameter="$(function)"`
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    is prohibited at all times *except* when an actual external command is invoked, e.g. `sort(1)`
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    or `sed(1)`.  
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    This is necessary due to the very significant cost of the mentioned pattern, particularly concerning
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    primitive e.g. list or string processing functions with high contention.
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15) If a function is to return, produce, evaluate to, etc. an arbitrary value apart from the exit status,
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    it shall do so by receiving references to the target variables in the callers' scope from the caller
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    prefixed with a single `$` character, e.g. `function \$parameter` and `function() {
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    local _fn_rparameter="${1#\$}"; [..]; }` which are then set with `eval` expressions: `
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    function() { local _fn_rparameter="${1#\$}"; [...]; eval ${_fn_rparameter}=\'a b c\'; };` Refer to
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    11)-13) for the rules concerning `eval`.  
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    This is necessary due to 14) as well as the absence of any other calling convention other than using
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    implicit global variables, e.g.: `function1() { VARIABLE=; function2; }; function2() { VARIABLE=1;
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    }`
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[//]: # "{{{ 5. References"
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## 5. References
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* ``Sun, 25 Apr 2016 09:04:08 +0000 [1]``musl FAQ  
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* ``Wed, 04 Mar 2020 13:36:19 +0000 [2]``midipix - what is midipix, and how is it different?  
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* ``Wed, 29 Apr 2020 23:33:34 +0100 [3]``User Rights Assignment (Windows 10) - Windows security | Microsoft Docs  
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* ``Wed, 29 Apr 2020 23:33:50 +0100 [4]``Windows Vista Application Development Requirements for User Account Control Compatibility | Microsoft Docs  
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[Back to top](#table-of-contents)
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[//]: # "}}}"
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[modeline]: # ( vim: set tw=0: )