2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1991, 1993
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8 * modification, are permitted provided that the following conditions
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32 #include <sys/cdefs.h>
33 __SCCSID("@(#)exec.c 8.1 (Berkeley) 6/4/93");
34 __FBSDID("$FreeBSD$");
36 #include "namespace.h"
37 #include <sys/param.h>
47 #include "un-namespace.h"
48 #include "libc_private.h"
50 extern char **environ;
52 static const char execvPe_err_preamble[] = "execvP: ";
53 static const char execvPe_err_trailer[] = ": path too long\n";
56 execl(const char *name, const char *arg, ...)
64 while (va_arg(ap, char *) != NULL)
67 argv = alloca((n + 1) * sizeof(*argv));
75 while ((argv[n] = va_arg(ap, char *)) != NULL)
78 return (_execve(name, __DECONST(char **, argv), environ));
82 execle(const char *name, const char *arg, ...)
91 while (va_arg(ap, char *) != NULL)
94 argv = alloca((n + 1) * sizeof(*argv));
102 while ((argv[n] = va_arg(ap, char *)) != NULL)
104 envp = va_arg(ap, char **);
106 return (_execve(name, __DECONST(char **, argv), envp));
110 execlp(const char *name, const char *arg, ...)
118 while (va_arg(ap, char *) != NULL)
121 argv = alloca((n + 1) * sizeof(*argv));
129 while ((argv[n] = va_arg(ap, char *)) != NULL)
132 return (execvp(name, __DECONST(char **, argv)));
136 execv(const char *name, char * const *argv)
138 (void)_execve(name, argv, environ);
143 execvp(const char *name, char * const *argv)
145 return (_execvpe(name, argv, environ));
149 execvPe(const char *name, const char *path, char * const *argv,
154 int eacces, save_errno;
155 char buf[MAXPATHLEN];
156 const char *bp, *np, *op, *p;
161 /* If it's an absolute or relative path name, it's easy. */
162 if (strchr(name, '/')) {
169 /* If it's an empty path name, fail in the usual POSIX way. */
178 np = strchrnul(op, ':');
181 * It's a SHELL path -- double, leading and trailing colons
182 * mean the current directory.
185 /* Empty component. */
189 /* Non-empty component. */
194 /* Advance to the next component or terminate after this. */
201 * If the path is too long complain. This is a possible
202 * security issue; given a way to make the path too long
203 * the user may execute the wrong program.
205 if (lp + ln + 2 > sizeof(buf)) {
206 (void)_write(STDERR_FILENO, execvPe_err_preamble,
207 sizeof(execvPe_err_preamble) - 1);
208 (void)_write(STDERR_FILENO, p, lp);
209 (void)_write(STDERR_FILENO, execvPe_err_trailer,
210 sizeof(execvPe_err_trailer) - 1);
215 bcopy(name, buf + lp + 1, ln);
216 buf[lp + ln + 1] = '\0';
218 retry: (void)_execve(bp, argv, envp);
227 for (cnt = 0; argv[cnt]; ++cnt)
231 * cnt may be 0 above; always allocate at least
232 * 3 entries so that we can at least fit "sh", bp, and
233 * the NULL terminator. We can rely on cnt to take into
234 * account the NULL terminator in all other scenarios,
235 * as we drop argv[0].
237 memp = alloca(MAX(3, cnt + 2) * sizeof(char *));
239 /* errno = ENOMEM; XXX override ENOEXEC? */
245 bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
251 (void)_execve(_PATH_BSHELL,
252 __DECONST(char **, memp), envp);
260 * We used to retry here, but sh(1) doesn't.
265 * EACCES may be for an inaccessible directory or
266 * a non-executable file. Call stat() to decide
267 * which. This also handles ambiguities for EFAULT
268 * and EIO, and undocumented errors like ESTALE.
269 * We hope that the race for a stat() is unimportant.
272 if (stat(bp, &sb) != 0)
274 if (save_errno == EACCES) {
291 execvP(const char *name, const char *path, char * const argv[])
293 return execvPe(name, path, argv, environ);
297 _execvpe(const char *name, char * const argv[], char * const envp[])
301 /* Get the path we're searching. */
302 if ((path = getenv("PATH")) == NULL)
303 path = _PATH_DEFPATH;
305 return (execvPe(name, path, argv, envp));