2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1991, 1993
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32 #include <sys/cdefs.h>
33 __SCCSID("@(#)exec.c 8.1 (Berkeley) 6/4/93");
34 #include "namespace.h"
35 #include <sys/param.h>
45 #include "un-namespace.h"
46 #include "libc_private.h"
48 static const char execvPe_err_preamble[] = "execvP: ";
49 static const char execvPe_err_trailer[] = ": path too long\n";
52 execl(const char *name, const char *arg, ...)
60 while (va_arg(ap, char *) != NULL)
63 argv = alloca((n + 1) * sizeof(*argv));
71 while ((argv[n] = va_arg(ap, char *)) != NULL)
74 return (_execve(name, __DECONST(char **, argv), environ));
78 execle(const char *name, const char *arg, ...)
87 while (va_arg(ap, char *) != NULL)
90 argv = alloca((n + 1) * sizeof(*argv));
98 while ((argv[n] = va_arg(ap, char *)) != NULL)
100 envp = va_arg(ap, char **);
102 return (_execve(name, __DECONST(char **, argv), envp));
106 execlp(const char *name, const char *arg, ...)
114 while (va_arg(ap, char *) != NULL)
117 argv = alloca((n + 1) * sizeof(*argv));
125 while ((argv[n] = va_arg(ap, char *)) != NULL)
128 return (execvp(name, __DECONST(char **, argv)));
132 execv(const char *name, char * const *argv)
134 (void)_execve(name, argv, environ);
139 execvp(const char *name, char * const *argv)
141 return (_execvpe(name, argv, environ));
145 execvPe(const char *name, const char *path, char * const *argv,
150 int eacces, save_errno;
151 char buf[MAXPATHLEN];
152 const char *bp, *np, *op, *p;
157 /* If it's an absolute or relative path name, it's easy. */
158 if (strchr(name, '/')) {
165 /* If it's an empty path name, fail in the usual POSIX way. */
174 np = strchrnul(op, ':');
177 * It's a SHELL path -- double, leading and trailing colons
178 * mean the current directory.
181 /* Empty component. */
185 /* Non-empty component. */
190 /* Advance to the next component or terminate after this. */
197 * If the path is too long complain. This is a possible
198 * security issue; given a way to make the path too long
199 * the user may execute the wrong program.
201 if (lp + ln + 2 > sizeof(buf)) {
202 (void)_write(STDERR_FILENO, execvPe_err_preamble,
203 sizeof(execvPe_err_preamble) - 1);
204 (void)_write(STDERR_FILENO, p, lp);
205 (void)_write(STDERR_FILENO, execvPe_err_trailer,
206 sizeof(execvPe_err_trailer) - 1);
211 bcopy(name, buf + lp + 1, ln);
212 buf[lp + ln + 1] = '\0';
214 retry: (void)_execve(bp, argv, envp);
223 for (cnt = 0; argv[cnt]; ++cnt)
227 * cnt may be 0 above; always allocate at least
228 * 3 entries so that we can at least fit "sh", bp, and
229 * the NULL terminator. We can rely on cnt to take into
230 * account the NULL terminator in all other scenarios,
231 * as we drop argv[0].
233 memp = alloca(MAX(3, cnt + 2) * sizeof(char *));
235 /* errno = ENOMEM; XXX override ENOEXEC? */
241 bcopy(argv + 1, memp + 2, cnt * sizeof(char *));
247 (void)_execve(_PATH_BSHELL,
248 __DECONST(char **, memp), envp);
256 * We used to retry here, but sh(1) doesn't.
261 * EACCES may be for an inaccessible directory or
262 * a non-executable file. Call stat() to decide
263 * which. This also handles ambiguities for EFAULT
264 * and EIO, and undocumented errors like ESTALE.
265 * We hope that the race for a stat() is unimportant.
268 if (stat(bp, &sb) != 0)
270 if (save_errno == EACCES) {
287 execvP(const char *name, const char *path, char * const argv[])
289 return execvPe(name, path, argv, environ);
293 _execvpe(const char *name, char * const argv[], char * const envp[])
297 /* Get the path we're searching. */
298 if ((path = getenv("PATH")) == NULL)
299 path = _PATH_DEFPATH;
301 return (execvPe(name, path, argv, envp));