build: Add a pkg-config file

The .pc are a better replacement for library detection and linking
usage, than libtool .la files or hardcoding the flags in the using
code.

Author: guillemj

.gitignore

@@ -1,6 +1,7 @@
 *.la
 *.lo
 *.o
+*.pc
 .deps
 .libs
 INSTALL

configure.ac

@@ -56,6 +56,7 @@ AC_CHECK_FUNCS([bzero isascii memset strchr strerror strrchr strstr strtol])
 
 AC_CONFIG_FILES([Makefile
                  lib/Makefile
+                 lib/libsysfs.pc
                  cmd/Makefile
                  test/Makefile])
 AC_CONFIG_HEADERS([config.h])

lib/Makefile.am

@@ -1,3 +1,8 @@
+EXTRA_DIST = libsysfs.pc.in
+
+pkgconfigdir = $(libdir)/pkgconfig
+pkgconfig_DATA = libsysfs.pc
+
 lib_LTLIBRARIES = libsysfs.la
 libsysfs_la_SOURCES = sysfs_utils.c sysfs_attr.c sysfs_class.c dlist.c \
       sysfs_device.c sysfs_driver.c sysfs_bus.c sysfs_module.c sysfs.h

lib/libsysfs.pc.in

@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: libsysfs
+Description: interface to Linux sysfs
+Version: @VERSION@
+URL: https://github.com/linux-ras/sysfsutils
+Libs: -L${libdir} -lsysfs
+Cflags: -I${includedir}