Pacman PKGINFO

Contents

Pacman PKGINFO

Issues

It seems that although Pacman is quite well documented in its usage for managing or building packages, the package format is completely undocumented.

Of course it says that a package file is a simple tar compressed with LZMA (xz), and that it must contain the files below, but their format is not clearly defined, at most hinted (in the case of .PKGINFO) or given templates and short explanation (in case of the other), see Creating packages:

.PKGINFO containing the package's meta-data;
.INSTALL giving hooks for various situations like pre- / post- install, upgrade or remove;
all the other files and directories with their full path (like etc/somepackage/someconf);
all the files are not rooted in /, i.e. they are relative;

Analysis

The empirical approach

To obtain some examples we could run the following command inside the packages cache (/var/cache/pacman/pkg):

find . -type f -name '*.pkg.tar.xz' -print -exec tar -xJf {} -O .PKGINFO \; -printf '\n\n' >/tmp/PKGINFO.txt

To see which options are present we could run:

grep -E -o -e '^[^ ]+\s*=' /tmp/PKGINFO.txt | sort -u

arch =
backup =
builddate =
conflict =
depend =
group =
license =
makepkgopt =
optdepend =
packager =
pkgbase =
pkgdesc =
pkgname =
pkgver =
provides =
replaces =
size =
url =

It seems that the general file syntax is the following:

lines starting with # which are ignored;
lines of the format property = value;
the same property could appear multiple times and it constitutes a list;

It seems that the following properties are not lists but singleton values: arch, builddate, packager, pkgbase, pkgdesc, pkgname, pkgver, size, url. All the others could have multiple values.

Their semantic and syntax seem to follow that provided in PKGBUILD (5).

The reverse engineering approach

We can shovel through the source code available at pacman.git:

makepkg write_pkginfo function;
pmpkg.py makepkg function;
libalpm parse_descfile function -- the definitive source;

Examples

Bash

# Generated by makepkg 4.0.3
# using fakeroot version 1.18.3
# Thu May 31 11:46:35 UTC 2012
pkgname = bash
pkgver = 4.2.029-1
pkgdesc = The GNU Bourne Again shell
url = http://www.gnu.org/software/bash/bash.html
builddate = 1338464794
packager = Allan McRae <allan@archlinux.org>
size = 3747840
arch = i686
license = GPL
group = base
backup = etc/bash.bashrc
backup = etc/bash.bash_logout
backup = etc/skel/.bashrc
backup = etc/skel/.bash_profile
backup = etc/skel/.bash_logout
depend = readline>=6.1
depend = glibc
provides = sh
makepkgopt = strip
makepkgopt = docs
makepkgopt = libtool
makepkgopt = emptydirs
makepkgopt = zipman
makepkgopt = purge
makepkgopt = !upx

GCC

# Generated by makepkg 4.0.3
# using fakeroot version 1.18.4
# Sat Jun 16 11:09:24 UTC 2012
pkgname = gcc
pkgbase = gcc
pkgver = 4.7.1-1
pkgdesc = The GNU Compiler Collection - C and C++ frontends
url = http://gcc.gnu.org
builddate = 1339844963
packager = Allan McRae <allan@archlinux.org>
size = 72290304
arch = i686
license = GPL
license = LGPL
license = FDL
license = custom
group = base-devel
depend = gcc-libs=4.7.1-1
depend = binutils>=2.22
depend = libmpc
depend = cloog
depend = ppl
makepkgopt = strip
makepkgopt = docs
makepkgopt = !libtool
makepkgopt = !emptydirs
makepkgopt = zipman
makepkgopt = purge
makepkgopt = !upx

GhostScript

# Generated by makepkg 4.0.1
# using fakeroot version 1.18.2
# Thu Feb  9 20:20:37 UTC 2012
pkgname = ghostscript
pkgver = 9.05-1
pkgdesc = An interpreter for the PostScript language
url = http://www.ghostscript.com/
builddate = 1328818837
packager = Andreas Radke <andyrtr@archlinux.org>
size = 46666752
arch = i686
license = GPL3
license = custom
optdepend = texlive-core: needed for dvipdf
optdepend = gtk2: needed for gsx
depend = libxt
depend = libcups
depend = fontconfig
depend = jasper
depend = zlib
depend = libpng>=1.5.7
depend = libjpeg
depend = libtiff>=4.0.0
depend = lcms
makepkgopt = strip
makepkgopt = docs
makepkgopt = !libtool
makepkgopt = emptydirs
makepkgopt = zipman
makepkgopt = purge
makepkgopt = !upx