Changes between Version 7 and Version 8 of CompilationGuide/Generic

Timestamp:

Dec 29, 2013, 12:46:26 PM (13 years ago)

Author:

Stefano Sabatini

Comment:

extend section about environment variables, fill the missing descriptions

CompilationGuide/Generic

@@ -62 +62 @@
 * PATH: defines the list of :-separated paths where the system looks for binaries. For example if you install your package in {{{/usr/local/}}}, you should update the PATH so that it will contain {{{/usr/local/bin}}}. This can be done for example through the command {{{export PATH=/usr/local/bin:$PATH}}}.
 * LD_LIBRARY_PATH: contains the :-separated paths where the system looks for libraries. For example if you install your package in {{{/usr/local/}}}, you should update the LD_LIBRARY_PATH so that it will contain {{{/usr/local/lib}}}. This can be done for example through the command {{{export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH}}}. This variable is sometimes deprecated in favor of the use of ldconfig.
-* CFLAGS
-* LDFLAGS
-* PKG_CONFIG_PATH
+* CFLAGS: contains flags used by the C compiler, usually include preprocessing directives like {{{-IPREFIX/include}}} or compilation flags. Custom CFLAGS are usually prefixed to the source package compiler flags by the source package build system. Alternatively many build systems allow to specify the configure option {{{-extra-cflags}}}. 
+* LDFLAGS: these are directives used by the linker, usually include linking directives like {{{-LPREFIX/lib}}} needed to find libraries installed in custom paths. Custom LDFLAGS are usually prefixed to the source package linker flags by the source package build system. Alternatively many build systems allow to specify the configure option {{{-extra-ldflags}}}.
+* PKG_CONFIG_PATH: contains the :-separated paths used by {{{pkg-config}}} to detect the pkg-config files used by many build systems to detect the custom CFLAGS/LDFLAGS used by a specific library.
 
 In case you installed a package in a non standard path, you need to update these environment libraries so that system tools will be able to detect the package components. This is especially required when running a configure script for a package relying on other installed libraries/headers/tools.