execvp.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
/*
* execlp(name, arg,...,0) (like execl, but does path search)
* execvp(name, argv) (like execv, but does path search)
*/
#pragma weak execlp = _execlp
#pragma weak execvp = _execvp
#include "synonyms.h"
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <alloca.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdlib.h>
static const char *execat(const char *, const char *, char *);
extern int __xpg4; /* defined in xpg4.c; 0 if not xpg4-compiled program */
/*VARARGS1*/
int
execlp(const char *name, const char *arg0, ...)
{
char **argp;
va_list args;
char **argvec;
int err;
int nargs = 0;
char *nextarg;
/*
* count the number of arguments in the variable argument list
* and allocate an argument vector for them on the stack,
* adding space for a terminating null pointer at the end
* and one additional space for argv[0] which is no longer
* counted by the varargs loop.
*/
va_start(args, arg0);
while (va_arg(args, char *) != (char *)0)
nargs++;
va_end(args);
/*
* load the arguments in the variable argument list
* into the argument vector and add the terminating null pointer
*/
va_start(args, arg0);
/* workaround for bugid 1242839 */
argvec = alloca((size_t)((nargs + 2) * sizeof (char *)));
nextarg = va_arg(args, char *);
argp = argvec;
*argp++ = (char *)arg0;
while (nargs-- && nextarg != (char *)0) {
*argp = nextarg;
argp++;
nextarg = va_arg(args, char *);
}
va_end(args);
*argp = (char *)0;
/*
* call execvp()
*/
err = execvp(name, argvec);
return (err);
}
int
execvp(const char *name, char *const *argv)
{
const char *pathstr;
char fname[PATH_MAX+2];
char *newargs[256];
int i;
const char *cp;
unsigned etxtbsy = 1;
int eacces = 0;
char *shpath;
static const char *sun_path = "/bin/sh";
static const char *xpg4_path = "/usr/xpg4/bin/sh";
static const char *shell = "sh";
if (*name == '\0') {
errno = ENOENT;
return (-1);
}
if ((pathstr = getenv("PATH")) == NULL) {
/*
* XPG4: pathstr is equivalent to CSPATH, except that
* :/usr/sbin is appended when root, and pathstr must end
* with a colon when not root. Keep these paths in sync
* with CSPATH in confstr.c. Note that pathstr must end
* with a colon when not root so that when name doesn't
* contain '/', the last call to execat() will result in an
* attempt to execv name from the current directory.
*/
if (geteuid() == 0 || getuid() == 0) {
if (__xpg4 == 0) { /* not XPG4 */
pathstr = "/usr/sbin:/usr/ccs/bin:/usr/bin";
} else { /* XPG4 (CSPATH + /usr/sbin) */
pathstr = "/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:"
"/opt/SUNWspro/bin:/usr/sbin";
}
} else {
if (__xpg4 == 0) { /* not XPG4 */
pathstr = "/usr/ccs/bin:/usr/bin:";
} else { /* XPG4 (CSPATH) */
pathstr = "/usr/xpg4/bin:/usr/ccs/bin:"
"/usr/bin:/opt/SUNWspro/bin:";
}
}
}
cp = strchr(name, '/')? (const char *)"": pathstr;
do {
cp = execat(cp, name, fname);
retry:
/*
* 4025035 and 4038378
* if a filename begins with a "-" prepend "./" so that
* the shell can't interpret it as an option
*/
if (*fname == '-') {
size_t size = strlen(fname) + 1;
if ((size + 2) > sizeof (fname)) {
errno = E2BIG;
return (-1);
}
(void) memmove(fname + 2, fname, size);
fname[0] = '.';
fname[1] = '/';
}
(void) execv(fname, argv);
switch (errno) {
case ENOEXEC:
if (__xpg4 == 0) { /* not XPG4 */
shpath = (char *)sun_path;
} else { /* XPG4 */
shpath = (char *)xpg4_path;
}
newargs[0] = (char *)shell;
newargs[1] = fname;
for (i = 1; (newargs[i + 1] = argv[i]) != NULL; ++i) {
if (i >= 254) {
errno = E2BIG;
return (-1);
}
}
(void) execv((const char *)shpath, newargs);
return (-1);
case ETXTBSY:
if (++etxtbsy > 5)
return (-1);
(void) sleep(etxtbsy);
goto retry;
case EACCES:
++eacces;
break;
case ENOMEM:
case E2BIG:
case EFAULT:
return (-1);
}
} while (cp);
if (eacces)
errno = EACCES;
return (-1);
}
static const char *
execat(const char *s1, const char *s2, char *si)
{
char *s;
int cnt = PATH_MAX + 1; /* number of characters in s2 */
s = si;
while (*s1 && *s1 != ':') {
if (cnt > 0) {
*s++ = *s1++;
cnt--;
} else
s1++;
}
if (si != s && cnt > 0) {
*s++ = '/';
cnt--;
}
while (*s2 && cnt > 0) {
*s++ = *s2++;
cnt--;
}
*s = '\0';
return (*s1 ? ++s1: 0);
}