NetBSD/lib/libc/gen/exec.c

266 lines
5.9 KiB
C
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1993-03-21 12:45:37 +03:00
/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)exec.c 5.9 (Berkeley) 6/17/91";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <paths.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
extern char **environ;
static char **
buildargv(ap, arg, envpp)
va_list ap;
const char *arg;
char ***envpp;
{
register size_t max, off;
register char **argv = NULL;
for (off = max = 0;; ++off) {
if (off >= max) {
max += 50; /* Starts out at 0. */
max *= 2; /* Ramp up fast. */
if (!(argv = realloc(argv, max * sizeof(char *))))
return(NULL);
if (off == 0) {
argv[0] = (char *)arg;
off = 1;
}
}
if (!(argv[off] = va_arg(ap, char *)))
break;
}
/* Get environment pointer if user supposed to provide one. */
if (envpp)
*envpp = va_arg(ap, char **);
return(argv);
}
int
#if __STDC__
execl(const char *name, const char *arg, ...)
#else
execl(name, arg, va_alist)
const char *name;
const char *arg;
va_dcl
#endif
{
va_list ap;
int sverrno;
char **argv;
#if __STDC__
va_start(ap, arg);
#else
va_start(ap);
#endif
if (argv = buildargv(ap, arg, (char ***)NULL))
(void)execve(name, argv, environ);
va_end(ap);
sverrno = errno;
free(argv);
errno = sverrno;
return(-1);
}
int
#if __STDC__
execle(const char *name, const char *arg, ...)
#else
execle(name, arg, va_alist)
const char *name;
const char *arg;
va_dcl
#endif
{
va_list ap;
int sverrno;
char **argv, **envp;
#if __STDC__
va_start(ap, arg);
#else
va_start(ap);
#endif
if (argv = buildargv(ap, arg, &envp))
(void)execve(name, argv, envp);
va_end(ap);
sverrno = errno;
free(argv);
errno = sverrno;
return(-1);
}
int
#if __STDC__
execlp(const char *name, const char *arg, ...)
#else
execlp(name, arg, va_alist)
const char *name;
const char *arg;
va_dcl
#endif
{
va_list ap;
int sverrno;
char **argv;
#if __STDC__
va_start(ap, arg);
#else
va_start(ap);
#endif
if (argv = buildargv(ap, arg, (char ***)NULL))
(void)execvp(name, argv);
va_end(ap);
sverrno = errno;
free(argv);
errno = sverrno;
return(-1);
}
int
execv(name, argv)
const char *name;
char * const *argv;
{
(void)execve(name, argv, environ);
return(-1);
}
int
execvp(name, argv)
const char *name;
char * const *argv;
{
register int lp, ln;
register char *p;
int eacces, etxtbsy;
char *bp, *cur, *path, buf[MAXPATHLEN];
/* If it's an absolute or relative path name, it's easy. */
if (index(name, '/')) {
bp = (char *)name;
cur = path = NULL;
goto retry;
}
bp = buf;
/* Get the path we're searching. */
if (!(path = getenv("PATH")))
path = _PATH_DEFPATH;
cur = path = strdup(path);
eacces = etxtbsy = 0;
while (p = strsep(&cur, ":")) {
/*
* It's a SHELL path -- double, leading and trailing colons
* mean the current directory.
*/
if (!*p) {
p = ".";
lp = 1;
} else
lp = strlen(p);
ln = strlen(name);
/*
* If the path is too long complain. This is a possible
* security issue; given a way to make the path too long
* the user may execute the wrong program.
*/
if (lp + ln + 2 > sizeof(buf)) {
(void)write(STDERR_FILENO, "execvp: ", 8);
(void)write(STDERR_FILENO, p, lp);
(void)write(STDERR_FILENO, ": path too long\n", 16);
continue;
}
bcopy(p, buf, lp);
buf[lp] = '/';
bcopy(name, buf + lp + 1, ln);
buf[lp + ln + 1] = '\0';
retry: (void)execve(bp, argv, environ);
switch(errno) {
case EACCES:
eacces = 1;
break;
case ENOENT:
break;
case ENOEXEC: {
register size_t cnt;
register char **ap;
for (cnt = 0, ap = (char **)argv; *ap; ++ap, ++cnt);
if (ap = malloc((cnt + 2) * sizeof(char *))) {
bcopy(argv + 1, ap + 2, cnt * sizeof(char *));
ap[0] = "sh";
ap[1] = bp;
(void)execve(_PATH_BSHELL, ap, environ);
free(ap);
}
goto done;
}
case ETXTBSY:
if (etxtbsy < 3)
(void)sleep(++etxtbsy);
goto retry;
default:
goto done;
}
}
if (eacces)
errno = EACCES;
else if (!errno)
errno = ENOENT;
done: if (path)
free(path);
return(-1);
}