| 1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * %sccs.include.redist.c% |
| 6 | */ |
| 7 | |
| 8 | #if defined(LIBC_SCCS) && !defined(lint) |
| 9 | static char sccsid[] = "@(#)exec.c 5.8 (Berkeley) %G%"; |
| 10 | #endif /* LIBC_SCCS and not lint */ |
| 11 | |
| 12 | #include <sys/param.h> |
| 13 | #include <sys/types.h> |
| 14 | #include <errno.h> |
| 15 | #include <unistd.h> |
| 16 | #include <stdlib.h> |
| 17 | #if __STDC__ |
| 18 | #include <stdarg.h> |
| 19 | #else |
| 20 | #include <varargs.h> |
| 21 | #endif |
| 22 | #include <string.h> |
| 23 | #include <stdio.h> |
| 24 | #include <paths.h> |
| 25 | |
| 26 | extern char **environ; |
| 27 | |
| 28 | static char ** |
| 29 | buildargv(ap, arg, envpp) |
| 30 | va_list ap; |
| 31 | const char *arg; |
| 32 | char ***envpp; |
| 33 | { |
| 34 | register size_t max, off; |
| 35 | register char **argv = NULL; |
| 36 | |
| 37 | for (off = max = 0;; ++off) { |
| 38 | if (off >= max) { |
| 39 | max += 50; /* Starts out at 0. */ |
| 40 | max *= 2; /* Ramp up fast. */ |
| 41 | if (!(argv = realloc(argv, max * sizeof(char *)))) |
| 42 | return(NULL); |
| 43 | if (off == 0) { |
| 44 | argv[0] = (char *)arg; |
| 45 | off = 1; |
| 46 | } |
| 47 | } |
| 48 | if (!(argv[off] = va_arg(ap, char *))) |
| 49 | break; |
| 50 | } |
| 51 | /* Get environment pointer if need user supposed to provide one. */ |
| 52 | if (envpp) |
| 53 | *envpp = va_arg(ap, char **); |
| 54 | return(argv); |
| 55 | } |
| 56 | |
| 57 | int |
| 58 | #if __STDC__ |
| 59 | execl(const char *name, const char *arg, ...) |
| 60 | #else |
| 61 | execl(name, arg, va_alist) |
| 62 | const char *name; |
| 63 | const char *arg; |
| 64 | va_dcl |
| 65 | #endif |
| 66 | { |
| 67 | va_list ap; |
| 68 | int sverrno; |
| 69 | char **argv; |
| 70 | |
| 71 | #if __STDC__ |
| 72 | va_start(ap, arg); |
| 73 | #else |
| 74 | va_start(ap); |
| 75 | #endif |
| 76 | if (argv = buildargv(ap, arg, (char ***)NULL)) |
| 77 | (void)execve(name, argv, environ); |
| 78 | va_end(ap); |
| 79 | sverrno = errno; |
| 80 | free(argv); |
| 81 | errno = sverrno; |
| 82 | return(-1); |
| 83 | } |
| 84 | |
| 85 | int |
| 86 | #if __STDC__ |
| 87 | execle(const char *name, const char *arg, ...) |
| 88 | #else |
| 89 | execle(name, arg, va_alist) |
| 90 | const char *name; |
| 91 | const char *arg; |
| 92 | va_dcl |
| 93 | #endif |
| 94 | { |
| 95 | va_list ap; |
| 96 | int sverrno; |
| 97 | char **argv, **envp; |
| 98 | |
| 99 | #if __STDC__ |
| 100 | va_start(ap, arg); |
| 101 | #else |
| 102 | va_start(ap); |
| 103 | #endif |
| 104 | if (argv = buildargv(ap, arg, &envp)) |
| 105 | (void)execve(name, argv, envp); |
| 106 | va_end(ap); |
| 107 | sverrno = errno; |
| 108 | free(argv); |
| 109 | errno = sverrno; |
| 110 | return(-1); |
| 111 | } |
| 112 | |
| 113 | int |
| 114 | #if __STDC__ |
| 115 | execlp(const char *name, const char *arg, ...) |
| 116 | #else |
| 117 | execlp(name, arg, va_alist) |
| 118 | const char *name; |
| 119 | const char *arg; |
| 120 | va_dcl |
| 121 | #endif |
| 122 | { |
| 123 | va_list ap; |
| 124 | int sverrno; |
| 125 | char **argv; |
| 126 | |
| 127 | #if __STDC__ |
| 128 | va_start(ap, arg); |
| 129 | #else |
| 130 | va_start(ap); |
| 131 | #endif |
| 132 | if (argv = buildargv(ap, arg, (char ***)NULL)) |
| 133 | (void)execvp(name, argv); |
| 134 | va_end(ap); |
| 135 | sverrno = errno; |
| 136 | free(argv); |
| 137 | errno = sverrno; |
| 138 | return(-1); |
| 139 | } |
| 140 | |
| 141 | int |
| 142 | execv(name, argv) |
| 143 | const char *name; |
| 144 | char * const *argv; |
| 145 | { |
| 146 | (void)execve(name, argv, environ); |
| 147 | return(-1); |
| 148 | } |
| 149 | |
| 150 | int |
| 151 | execvp(name, argv) |
| 152 | const char *name; |
| 153 | char * const *argv; |
| 154 | { |
| 155 | register char *p; |
| 156 | int eacces, etxtbsy; |
| 157 | char *bp, *cur, *path, buf[MAXPATHLEN]; |
| 158 | |
| 159 | /* If it's an absolute or relative path name, it's easy. */ |
| 160 | if (index(name, '/')) { |
| 161 | bp = (char *)name; |
| 162 | cur = path = NULL; |
| 163 | goto retry; |
| 164 | } |
| 165 | bp = buf; |
| 166 | |
| 167 | /* Get the path we're searching. */ |
| 168 | if (!(path = getenv("PATH"))) |
| 169 | path = _PATH_DEFPATH; |
| 170 | cur = path = strdup(path); |
| 171 | |
| 172 | eacces = etxtbsy = 0; |
| 173 | while (p = strsep(&cur, ":")) { |
| 174 | /* |
| 175 | * It's a SHELL path -- double, leading and trailing colons |
| 176 | * mean the current directory. |
| 177 | */ |
| 178 | if (!*p) |
| 179 | p = "."; |
| 180 | (void)snprintf(buf, sizeof(buf), "%s/%s", p, name); |
| 181 | |
| 182 | retry: (void)execve(bp, argv, environ); |
| 183 | switch(errno) { |
| 184 | case EACCES: |
| 185 | eacces = 1; |
| 186 | break; |
| 187 | case ENOENT: |
| 188 | break; |
| 189 | case ENOEXEC: { |
| 190 | register size_t cnt; |
| 191 | register char **ap; |
| 192 | |
| 193 | for (cnt = 0, ap = (char **)argv; *ap; ++ap, ++cnt); |
| 194 | if (ap = malloc((cnt + 2) * sizeof(char *))) { |
| 195 | bcopy(argv + 1, ap + 2, cnt * sizeof(char *)); |
| 196 | ap[0] = "sh"; |
| 197 | ap[1] = bp; |
| 198 | (void)execve(_PATH_BSHELL, ap, environ); |
| 199 | free(ap); |
| 200 | } |
| 201 | goto done; |
| 202 | } |
| 203 | case ETXTBSY: |
| 204 | if (etxtbsy < 3) |
| 205 | (void)sleep(++etxtbsy); |
| 206 | goto retry; |
| 207 | default: |
| 208 | goto done; |
| 209 | } |
| 210 | } |
| 211 | if (eacces) |
| 212 | errno = EACCES; |
| 213 | else if (!errno) |
| 214 | errno = ENOENT; |
| 215 | done: if (path) |
| 216 | free(path); |
| 217 | return(-1); |
| 218 | } |