New --reexec option.

This helps with setuid hash bang scripting on Mac OS,
and other plaforms where the interpreter executed out
of a hash bang script runs with orinary privilege,
even if marked setuid.

* sysif.c (exec_wrap): Static function turns extern.

* sysif.h (exec-wrap): Declared.

* txr.1: Documented --reexec. Added notes about setuid under
Hash Bang Support.

* txr.c (help): List --reexec option.
(txr_main): Implement --reexec option.

1 files changed, 8 insertions, 0 deletions

diff --git a/txr.c b/txr.c
index 5a79611e..b8e6267f 100644
--- a/txr.c
+++ b/txr.c
@@ -153,6 +153,9 @@ static void help(void)
 "--compat=N             Synonym for -C N\n"
 "--gc-delta=N           Invoke garbage collection when malloc activity\n"
 "                       increments by N megabytes since last collection.\n"
+#if HAVE_FORK_STUFF
+"--reexec               Re-execute TXR with remaining arguments.\n"
+#endif
 "--debug-autoload       Allow debugger to step through library auto-loading.\n"
 "--debug-expansion      Allow debugger to step through macro-expansion of query.\n"
 "--yydebug              Debug Yacc parser, if compiled with YYDEBUG support.\n"
@@ -603,6 +606,11 @@ int txr_main(int argc, char **argv)
       } else if (equal(opt, lit("lisp"))) {
         txr_lisp_p = t;
         continue;
+#if HAVE_FORK_STUFF
+      } else if (equal(opt, lit("reexec"))) {
+        exec_wrap(prog_path, arg_list);
+        return EXIT_FAILURE;
+#endif
       } else if (equal(opt, lit("debugger"))) {
         drop_privilege();
 #if CONFIG_DEBUG_SUPPORT