allow process exit status to be determined by macros

* Any value left on the numeric stack now determines the exit code.
  This ensures you can call n^C as the SciTECO version of exit(n).
  It will also work with n$$ in the top level macro.
  But you don't necessarily need any of these commands.
* Could be useful in shell scripting as in
  `sciteco -e "@EB/file/ :@S/foo/\"F1'"` to fail `foo` is not found.

2 files changed, 18 insertions, 5 deletions

diff --git a/src/core-commands.c b/src/core-commands.c
index 141ce0a..337e8df 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -1320,7 +1320,7 @@ teco_state_control_xor(teco_machine_main_t *ctx, GError **error)
 }
 
 /*$ ^C exit
- * ^C -- Exit program immediately
+ * [n]^C -- Exit program immediately
  *
  * Lets the top-level macro return immediately
  * regardless of the current macro invocation frame.
@@ -1333,6 +1333,10 @@ teco_state_control_xor(teco_machine_main_t *ctx, GError **error)
  * effectively just like \(lq-EX\fB$$\fP\(rq
  * (when executed in the top-level macro at least).
  *
+ * Any numeric parameter is returned by the process
+ * as its exit status.
+ * By default, the success code is returned.
+ *
  * The \fBquit\fP hook is still executed.
  */
 static void
@@ -1678,6 +1682,9 @@ teco_state_escape_input(teco_machine_main_t *ctx, gunichar chr, GError **error)
 	 * Returning from the top-level macro in batch mode
 	 * will exit the program or start up interactive mode depending
 	 * on whether program exit has been requested.
+	 * If \fB$$\fP exits the program, any remaining numeric parameter
+	 * is returned by the process as its exit status.
+	 * By default, the success code is returned.
 	 * \(lqEX\fB$$\fP\(rq is thus a common idiom to exit
 	 * prematurely.
 	 *
diff --git a/src/main.c b/src/main.c
index 05f8c41..e57ab6f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -35,6 +35,7 @@
 #endif
 
 #include "sciteco.h"
+#include "expressions.h"
 #include "file-utils.h"
 #include "cmdline.h"
 #include "interface.h"
@@ -337,6 +338,7 @@ main(int argc, char **argv)
 #endif
 {
 	g_autoptr(GError) error = NULL;
+	teco_int_t ret = EXIT_SUCCESS;
 
 #ifdef DEBUG_PAUSE
 	/* Windows debugging hack (see above) */
@@ -461,7 +463,8 @@ main(int argc, char **argv)
 		}
 		g_clear_error(&error);
 
-		if (!teco_ed_hook(TECO_ED_HOOK_QUIT, &error))
+		if (!teco_expressions_pop_num_calc(&ret, EXIT_SUCCESS, &error) ||
+		    !teco_ed_hook(TECO_ED_HOOK_QUIT, &error))
 			goto cleanup;
 		goto cleanup;
 	}
@@ -499,7 +502,8 @@ main(int argc, char **argv)
 		g_clear_error(&error);
 
 		if (teco_quit_requested) {
-			if (!teco_ed_hook(TECO_ED_HOOK_QUIT, &error))
+			if (!teco_expressions_pop_num_calc(&ret, EXIT_SUCCESS, &error) ||
+			    !teco_ed_hook(TECO_ED_HOOK_QUIT, &error))
 				goto cleanup;
 			goto cleanup;
 		}
@@ -553,8 +557,10 @@ main(int argc, char **argv)
 		goto cleanup;
 
 cleanup:
-	if (error != NULL)
+	if (error != NULL) {
 		teco_error_display_full(error);
+		ret = EXIT_FAILURE;
+	}
 
 #ifndef NDEBUG
 	teco_ring_cleanup();
@@ -565,5 +571,5 @@ cleanup:
 #endif
 	teco_interface_cleanup();
 
-	return error ? EXIT_FAILURE : EXIT_SUCCESS;
+	return ret;
 }