It is much easier if you use GNU Automake instead of writing your own
Makefiles. If you do that, you do not have to worry about finding and
libgcrypt-config script at all.
Libgcrypt provides an extension to Automake that does all
the work for you.
Check whether Libgcrypt (at least version minimum-version, if given) exists on the host system. If it is found, execute action-if-found, otherwise do action-if-not-found, if given.
Additionally, the function defines
LIBGCRYPT_CFLAGS to the
flags needed for compilation of the program to find the
gcrypt.h header file, and
LIBGCRYPT_LIBS to the linker
flags needed to link the program to the Libgcrypt library. If the
used helper script does not match the target type you are building for
a warning is printed and the string
libgcrypt is appended to the
This macro searches for
libgcrypt-config along the PATH. If
you are cross-compiling, it is useful to set the environment variable
SYSROOT to the top directory of your target. The macro will
then first look for the helper program in the bin directory
below that top directory. An absolute directory name must be used for
SYSROOT. Finally, if the configure command line option
--with-libgcrypt-prefix is used, only its value is used for the top
directory below which the helper script is expected.
You can use the defined Autoconf variables like this in your Makefile.am:
AM_CPPFLAGS = $(LIBGCRYPT_CFLAGS) LDADD = $(LIBGCRYPT_LIBS)