1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/param.h> 39 #include <sys/types.h> 40 #include <errno.h> 41 #include <unistd.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <stdio.h> 45 #include <paths.h> 46 47 #if __STDC__ 48 #include <stdarg.h> 49 #else 50 #include <varargs.h> 51 #endif 52 53 extern char **environ; 54 55 static char ** 56 buildargv(ap, arg, envpp) 57 va_list ap; 58 const char *arg; 59 char ***envpp; 60 { 61 static int memsize; 62 static char **argv; 63 register int off; 64 65 argv = NULL; 66 for (off = 0;; ++off) { 67 if (off >= memsize) { 68 memsize += 50; /* Starts out at 0. */ 69 memsize *= 2; /* Ramp up fast. */ 70 if (!(argv = realloc(argv, memsize * sizeof(char *)))) { 71 memsize = 0; 72 return (NULL); 73 } 74 if (off == 0) { 75 argv[0] = (char *)arg; 76 off = 1; 77 } 78 } 79 if (!(argv[off] = va_arg(ap, char *))) 80 break; 81 } 82 /* Get environment pointer if user supposed to provide one. */ 83 if (envpp) 84 *envpp = va_arg(ap, char **); 85 return (argv); 86 } 87 88 int 89 #if __STDC__ 90 execl(const char *name, const char *arg, ...) 91 #else 92 execl(name, arg, va_alist) 93 const char *name; 94 const char *arg; 95 va_dcl 96 #endif 97 { 98 va_list ap; 99 int sverrno; 100 char **argv; 101 102 #if __STDC__ 103 va_start(ap, arg); 104 #else 105 va_start(ap); 106 #endif 107 if (argv = buildargv(ap, arg, NULL)) 108 (void)execve(name, argv, environ); 109 va_end(ap); 110 sverrno = errno; 111 free(argv); 112 errno = sverrno; 113 return (-1); 114 } 115 116 int 117 #if __STDC__ 118 execle(const char *name, const char *arg, ...) 119 #else 120 execle(name, arg, va_alist) 121 const char *name; 122 const char *arg; 123 va_dcl 124 #endif 125 { 126 va_list ap; 127 int sverrno; 128 char **argv, **envp; 129 130 #if __STDC__ 131 va_start(ap, arg); 132 #else 133 va_start(ap); 134 #endif 135 if (argv = buildargv(ap, arg, &envp)) 136 (void)execve(name, argv, envp); 137 va_end(ap); 138 sverrno = errno; 139 free(argv); 140 errno = sverrno; 141 return (-1); 142 } 143 144 int 145 #if __STDC__ 146 execlp(const char *name, const char *arg, ...) 147 #else 148 execlp(name, arg, va_alist) 149 const char *name; 150 const char *arg; 151 va_dcl 152 #endif 153 { 154 va_list ap; 155 int sverrno; 156 char **argv; 157 158 #if __STDC__ 159 va_start(ap, arg); 160 #else 161 va_start(ap); 162 #endif 163 if (argv = buildargv(ap, arg, NULL)) 164 (void)execvp(name, argv); 165 va_end(ap); 166 sverrno = errno; 167 free(argv); 168 errno = sverrno; 169 return (-1); 170 } 171 172 int 173 execv(name, argv) 174 const char *name; 175 char * const *argv; 176 { 177 (void)execve(name, argv, environ); 178 return (-1); 179 } 180 181 int 182 execvp(name, argv) 183 const char *name; 184 char * const *argv; 185 { 186 static int memsize; 187 static char **memp; 188 register int cnt, lp, ln; 189 register char *p; 190 int eacces, etxtbsy; 191 char *bp, *cur, *path, buf[MAXPATHLEN]; 192 193 /* If it's an absolute or relative path name, it's easy. */ 194 if (index(name, '/')) { 195 bp = (char *)name; 196 cur = path = NULL; 197 goto retry; 198 } 199 bp = buf; 200 201 /* Get the path we're searching. */ 202 if (!(path = getenv("PATH"))) 203 path = _PATH_DEFPATH; 204 cur = path = strdup(path); 205 206 eacces = etxtbsy = 0; 207 while (p = strsep(&cur, ":")) { 208 /* 209 * It's a SHELL path -- double, leading and trailing colons 210 * mean the current directory. 211 */ 212 if (!*p) { 213 p = "."; 214 lp = 1; 215 } else 216 lp = strlen(p); 217 ln = strlen(name); 218 219 /* 220 * If the path is too long complain. This is a possible 221 * security issue; given a way to make the path too long 222 * the user may execute the wrong program. 223 */ 224 if (lp + ln + 2 > sizeof(buf)) { 225 (void)write(STDERR_FILENO, "execvp: ", 8); 226 (void)write(STDERR_FILENO, p, lp); 227 (void)write(STDERR_FILENO, ": path too long\n", 16); 228 continue; 229 } 230 bcopy(p, buf, lp); 231 buf[lp] = '/'; 232 bcopy(name, buf + lp + 1, ln); 233 buf[lp + ln + 1] = '\0'; 234 235 retry: (void)execve(bp, argv, environ); 236 switch(errno) { 237 case EACCES: 238 eacces = 1; 239 break; 240 case ENOENT: 241 break; 242 case ENOEXEC: 243 for (cnt = 0; argv[cnt]; ++cnt); 244 if ((cnt + 2) * sizeof(char *) > memsize) { 245 memsize = (cnt + 2) * sizeof(char *); 246 if ((memp = realloc(memp, memsize)) == NULL) { 247 memsize = 0; 248 goto done; 249 } 250 } 251 memp[0] = "sh"; 252 memp[1] = bp; 253 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 254 (void)execve(_PATH_BSHELL, memp, environ); 255 goto done; 256 case ETXTBSY: 257 if (etxtbsy < 3) 258 (void)sleep(++etxtbsy); 259 goto retry; 260 default: 261 goto done; 262 } 263 } 264 if (eacces) 265 errno = EACCES; 266 else if (!errno) 267 errno = ENOENT; 268 done: if (path) 269 free(path); 270 return (-1); 271 } 272