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-rw-r--r--posix/execlp.c59
1 files changed, 41 insertions, 18 deletions
diff --git a/posix/execlp.c b/posix/execlp.c
index f442c05d94..76b878ec6a 100644
--- a/posix/execlp.c
+++ b/posix/execlp.c
@@ -1,24 +1,25 @@
-/* Copyright (C) 1991, 1993, 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
+/* Copyright (C) 1991, 1993, 1996, 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
 
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
 
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
 
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB.  If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
 
 #include <unistd.h>
 #include <stdarg.h>
 #include <stddef.h>
+#include <string.h>
 
 /* Execute FILE, searching in the `PATH' environment variable if
    it contains no slashes, with all arguments after FILE until a
@@ -26,16 +27,38 @@ Cambridge, MA 02139, USA.  */
 int
 execlp (const char *file, const char *arg, ...)
 {
-  const char *argv[1024];
+  size_t argv_max = 1024;
+  const char **argv = alloca (argv_max * sizeof (const char *));
   unsigned int i;
   va_list args;
 
+  argv[0] = arg;
+
   va_start (args, arg);
+  i = 1;
+  do
+    {
+      if (i == argv_max)
+	{
+	  const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
 
-  argv[i = 0] = arg;
-  while (argv[i++] != NULL)
-    argv[i] = va_arg (args, const char *);
+	  if ((char *) nptr + argv_max == (char *) argv)
+	    {
+	      /* Stack grows down.  */
+	      argv = (const char **) memcpy (nptr, argv, i);
+	      argv_max += i;
+	    }
+	  else if ((char *) argv + i == (char *) nptr)
+	    /* Stack grows up.  */
+	    argv_max += i;
+	  else
+	    /* We have a hole in the stack.  */
+	    argv = (const char **) memcpy (nptr, argv, i);
+	}
 
+      argv[i] = va_arg (args, const char *);
+    }
+  while (argv[i++] != NULL);
   va_end (args);
 
   return execvp (file, (char *const *) argv);