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);
 }