Thank you Eric for the explanation. Let me explain what i have done: step 1: the hello.c code include <stdio.h> main( int argc, char *argv[] ) { printf( "Hello, world\n" ); } step2: compile gcc hello.c -o hello step3: t17.at # Process with autom4te to create an -*- Autotest -*- test suite. m4_define([AT_PACKAGE_STRING], [GNU Programming]) m4_define([AT_PACKAGE_BUGREPORT], [gnuprog2-devel@xxxxxxxxxxxxxxx]) # AT_PACKAGE_STRING([Hello],[v.1.0]) # AT_PACKAGE_BUGREPORT([autotest@xxxxxxx]) AT_INIT([hello]) AT_SETUP([hello]) AT_TESTED([hello]) AT_CHECK([hello],[],[[Hello, world ]]) AT_CLEANUP() step 4: execute hello $ ./hello Hello, world $ step 5: autom4te -l autotest t17.at -o t17_hello step 6: t17_hello script update PATH with the current working dir ## ------------- ## ## Actual tests. ## ## ------------- ## #AT_START_1 .. { set +x $as_echo "$at_srcdir/t17.at:11: hello" at_fn_check_prepare_trace "t17.at:11" ( $at_check_trace; hello ) >>"$at_stdout" 2>>"$at_stderr" at_status=$? at_failed=false $at_check_filter at_fn_diff_devnull "$at_stderr" || at_failed=: echo >>"$at_stdout"; $as_echo "Hello, world " | \ $at_diff - "$at_stdout" || at_failed=: at_fn_check_status 0 $at_status "$at_srcdir/t17.at:11" $at_failed && at_fn_log_failure $at_traceon; } .. #AT_STOP_1 step 7: $ ./t17_hello -x -v step 8: t17_hello.log # -*- compilation -*- 1. t17.at:9: testing hello ... ++ set +x /t17.at:11: hello ++ hello /t17.at:11: exit code was 13, expected 0 1. t17.at:9: 1. hello (t17.at:9): FAILED (t17.at:11) step 9: modift t17.at AT_CHECK([hello],[],[["Hello, world "]]) step 10: and do the same steps as above: t17_hello script: echo >>"$at_stdout"; $as_echo "\"Hello, world \"" | \ step 10: t17_hello.log 1. t18.at:9: testing hello ... ++ set +x /t18.at:11: hello ++ hello --- - 2013-03-07 14:01:44.798854464 +0100 +++ /media/wd40/TODOs/work/work_20130306/autotest/trial2b/t18_hello.dir/at-groups/1/stdout2013-03-07 14:01:44.791793357 +0100 @@ -1,2 +1,2 @@ -"Hello, world -" +Hello, world + /t18.at:11: exit code was 13, expected 0 1. t18.at:9: FAILED (t18.at:11) Please inform me where the error is. Thank you -- View this message in context: http://gnu-autoconf.7623.n7.nabble.com/meaning-autotest-exit-code-13-tp18573p18576.html Sent from the Gnu - Autoconf - General mailing list archive at Nabble.com. _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf