ac_prog_crontab

Check for the program crontab, if exists let script continue, else pops an error message

Besides checking existence, this macro also set these environment variables upon completion:

     CRONTAB = which crontab

AC_DEFUN([AC_PROG_CRONTAB],[
AC_REQUIRE([AC_EXEEXT])dnl
AC_PATH_PROG(CRONTAB, crontab$EXEEXT, nocommand)
if test "$CRONTAB" = nocommand; then
        AC_MSG_ERROR([crontab (needed for scheduled job) not found in $PATH])
fi;dnl
])