make xfunctions optionally longjump instead of exit.

use it for making NOFORK more practical.
touch: make it a NOFORK applet

5 files changed, 31 insertions, 12 deletions

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index 0d0ec2232..805b80187 100644
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -77,7 +77,7 @@ void complain_copyfd_and_die(off_t sz)
 	if (sz != -1)
 		bb_error_msg_and_die("short read");
 	/* if sz == -1, bb_copyfd_XX already complained */
-	exit(xfunc_error_retval);
+	sleep_and_die();
 }
 #endif
 
@@ -97,7 +97,7 @@ void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
 	if (sz != -1)
 		bb_error_msg_and_die("short read");
 	/* if sz == -1, bb_copyfd_XX already complained */
-	exit(xfunc_error_retval);
+	sleep_and_die();
 }
 
 off_t bb_copyfd_eof(int fd1, int fd2)
diff --git a/libbb/error_msg_and_die.c b/libbb/error_msg_and_die.c
index 7c5a4ebe9..39178a3ce 100644
--- a/libbb/error_msg_and_die.c
+++ b/libbb/error_msg_and_die.c
@@ -7,18 +7,19 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <stdio.h>
-#include <errno.h>
-#include <string.h>
-#include <stdlib.h>
 #include "libbb.h"
 
 int die_sleep;
+jmp_buf die_jmp;
 
 void sleep_and_die(void)
 {
-	if (die_sleep)
+	if (die_sleep) {
+		/* Special case: don't die, but jump */
+		if (die_sleep < 0)
+			longjmp(die_jmp, xfunc_error_retval);
 		sleep(die_sleep);
+	}
 	exit(xfunc_error_retval);
 }
 
diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index dec97d743..28b47974e 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -457,6 +457,7 @@ getopt32(int argc, char **argv, const char *applet_opts, ...)
 
 	/* In case getopt32 was already called, reinit some state */
 	optind = 1;
+	/* optarg = NULL; opterr = 0; optopt = 0; ?? */
 
 	/* Note: just "getopt() <= 0" will not work good for
 	 * "fake" short options, like this one:
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index d25693917..286ee2678 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -115,11 +115,27 @@ int spawn_and_wait(char **argv)
 			char **pp = argv;
 			while (*++pp)
 				argc++;
-#ifdef BB_NOMMU
-			return a->main(argc, argv);
-#else
+#ifndef BB_NOMMU
 			if (a->nofork)
-				return a->main(argc, argv);
+#endif
+			{
+				int old_sleep = die_sleep;
+				die_sleep = -1; /* special flag */
+				/* sleep_and_die() checks for it */
+				rc = setjmp(die_jmp);
+				if (!rc) {
+					const struct BB_applet *old_a = current_applet;
+					current_applet = a;
+					applet_name = a->name;
+// what else should we save/restore?
+					rc = a->main(argc, argv);
+					current_applet = old_a;
+					applet_name = old_a->name;					
+				}
+				die_sleep = old_sleep;
+				return rc;
+			}
+#ifndef BB_NOMMU	/* MMU only */
 			/* a->noexec is true */
 			rc = fork();
 			if (rc)
@@ -135,6 +151,7 @@ int spawn_and_wait(char **argv)
 	return wait4pid(rc);
 }
 
+
 #if 0 //ndef BB_NOMMU
 // Die with an error message if we can't daemonize.
 void xdaemon(int nochdir, int noclose)
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 0cf2005ac..fa4a15236 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -476,7 +476,7 @@ void xprint_and_close_file(FILE *file)
 	fflush(stdout);
 	// copyfd outputs error messages for us.
 	if (bb_copyfd_eof(fileno(file), 1) == -1)
-		exit(xfunc_error_retval);
+		sleep_and_die();
 
 	fclose(file);
 }