b0df72f4fb
1998-02-27 Ulrich Drepper <drepper@cygnus.com> * posix/execlp.c: POSIX.1 says that argv[0] *should* be provided, but does not require it. Handle missing argv[] values gracefully. * posix/execl.c: Likewise. * posix/execle.c: Likewise.
66 lines
2.0 KiB
C
66 lines
2.0 KiB
C
/* Copyright (C) 1991, 1993, 1996, 1997, 1998 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <alloca.h>
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#include <unistd.h>
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#include <stdarg.h>
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#include <stddef.h>
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#include <string.h>
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/* Execute FILE, searching in the `PATH' environment variable if
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it contains no slashes, with all arguments after FILE until a
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NULL pointer and environment from `environ'. */
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int
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execlp (const char *file, const char *arg, ...)
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{
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size_t argv_max = 1024;
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const char **argv = alloca (argv_max * sizeof (const char *));
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unsigned int i;
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va_list args;
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argv[0] = arg;
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va_start (args, arg);
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i = 0;
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while (argv[i++] != NULL)
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{
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if (i == argv_max)
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{
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const char **nptr = alloca ((argv_max *= 2) * sizeof (const char *));
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if ((char *) nptr + argv_max == (char *) argv)
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{
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/* Stack grows down. */
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argv = (const char **) memcpy (nptr, argv, i);
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argv_max += i;
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}
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else if ((char *) argv + i == (char *) nptr)
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/* Stack grows up. */
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argv_max += i;
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else
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/* We have a hole in the stack. */
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argv = (const char **) memcpy (nptr, argv, i);
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}
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argv[i] = va_arg (args, const char *);
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}
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va_end (args);
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return execvp (file, (char *const *) argv);
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}
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