# ===========================================================================

#  https://www.gnu.org/software/autoconf-archive/ax_check_posix_regcomp.html

# ===========================================================================

#

# SYNOPSIS

#

#   AX_CHECK_POSIX_REGCOMP

#

# DESCRIPTION

#

#   Check that the POSIX compliant regular expression compiler is available

#   in the POSIX specified manner, and it works. If it fails, we have a

#   backup -- use gnu-regex.

#

# LICENSE

#

#   Copyright (c) 2008 Bruce Korb <bkorb@gnu.org>

#

#   Copying and distribution of this file, with or without modification, are

#   permitted in any medium without royalty provided the copyright notice

#   and this notice are preserved. This file is offered as-is, without any

#   warranty.

#serial 6

AU_ALIAS([AG_CHECK_POSIX_REGCOMP], [AX_CHECK_POSIX_REGCOMP])

AC_DEFUN([AX_CHECK_POSIX_REGCOMP],[

    AC_MSG_CHECKING([whether POSIX compliant regcomp()/regexec()])

    AC_CACHE_VAL([ax_cv_posix_regcomp],[

    AC_TRY_RUN([

#include <sys/types.h>

#include <regex.h>

int main() {

    int flags = REG_EXTENDED|REG_ICASE|REG_NEWLINE;

    regex_t  re;

    if (regcomp( &re, "^.*$", flags  ) != 0)

        return 1;

    return regcomp( &re, "yes.*|no.*", flags  );

}],

    [ax_cv_posix_regcomp=yes],[ax_cv_posix_regcomp=no],[ax_cv_posix_regcomp=no]

    ) # end of TRY_RUN]) # end of CACHE_VAL

    AC_MSG_RESULT([$ax_cv_posix_regcomp])

    if test "$ax_cv_posix_regcomp" = "yes"; then

        AC_DEFINE(HAVE_POSIX_REGCOMP, 1,

            [Define this if POSIX compliant regcomp()/regexec()])

    fi

]) # end of AC_DEFUN of AX_CHECK_POSIX_REGCOMP