pkg-config

/.
/usr
/usr/share
/usr/share/aclocal
/usr/share/aclocal/pkg.m4
/usr/share/man
/usr/share/man/man1
/usr/share/man/man1/pkg-config.1.gz
/usr/share/pkgconfig
/usr/share/pkg-config-dpkghook
/usr/share/doc
/usr/share/doc/pkg-config
/usr/share/doc/pkg-config/README
/usr/share/doc/pkg-config/copyright
/usr/share/doc/pkg-config/changelog.Debian.gz
/usr/share/doc/pkg-config/pkg-config-guide.html
/usr/share/doc/pkg-config/NEWS.gz
/usr/share/doc/pkg-config/AUTHORS
/usr/share/pkg-config-crosswrapper
/usr/lib
/usr/lib/pkgconfig
/usr/lib/pkg-config.multiarch
/usr/bin
/usr/bin/x86_64-pc-linux-gnu-pkg-config
/usr/bin/pkg-config
/etc
/etc/dpkg
/etc/dpkg/dpkg.cfg.d
/etc/dpkg/dpkg.cfg.d/pkg-config-hook-config

这个东西可以做什么

生成编译选项 和 连接选项

怎么做

常用过的选项就这两个

$ pkg-config  --cflags lua5.2
-I/usr/include/lua5.2
$ pkg-config  --libs lua5.2
-llua5.2

$ pkg-config --cflags zlib
-I/usr/local/include
$ pkg-config --libs zlib
-L/usr/local/lib -lz

更实际的用户 是 以
$(pkg-config  --cflags lua5.2) 或者
`pkg-config  --cflags lua5.2`
加载到命令行中运行
gcc -c test.c `pkg-config  --cflags lua5.2` -o test.o
gcc test.o main.o `pkg-config  --libs lua5.2`

或者 Makefile 中添加
CFLAGS += `pkg-config --cflags sqlite3`
LDFLAGS += `pkg-config --libs sqlite3`

命令执行的过程

pkg-config  option xxx

解析 xxx.pc文件

xxx.pc 在哪里找

标准目录下的 pkgconfig 里面
一般编译源码的时候会生成 .pc文件,然后安装的时候安装到相应目录.


系统中有 这么多 pkgconfig
$ locate pkgconfig |xargs file |awk '/directory/ {print $1}' | sed 's/://'
/usr/lib/pkgconfig
/usr/lib/i386-linux-gnu/pkgconfig
/usr/local/lib/pkgconfig
/usr/share/pkgconfig



pkg-config looks in
/usr/lib/pkgconfig
/usr/share/pkgconfig
/usr/local/lib/pkgconfig
/usr/local/share/pkgconfig

PKG_CONFIG_PATH
export PKG_CONFIG_PATH=/opt/gtk/lib/pkgconfig:$PKG_CONFIG_PATH

xxx.pc 文件的内容


示例1:
prefix=/usr/local
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
sharedlibdir=${libdir}
includedir=${prefix}/include

Name: xxx
Description: xxx compression library
Version: 1.2.8

Requires:
Libs: -L${libdir} -L${sharedlibdir} -lz
Cflags: -I${includedir}


man手册中的示例:
Here is an example file:
# This is a comment
prefix=/home/hp/unst   # this defines a variable
exec_prefix=${prefix}  # defining another variable in terms of the first
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Name: GObject                            # human-readable name
Description: Object/type system for GLib # human-readable description
Version: 1.3.1
URL: http://www.gtk.org

Requires: glib-2.0 = 1.3.1
Conflicts: foobar <= 4.5
Libs: -L${libdir} -lgobject-1.3
Libs.private: -lm
Cflags: -I${includedir}/glib-2.0 -I${libdir}/glib/include