1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)cd.c 8.2 (Berkeley) 5/4/95 37 * $FreeBSD: src/bin/sh/cd.c,v 1.35 2006/06/12 21:06:00 stefanf Exp $ 38 * $DragonFly: src/bin/sh/cd.c,v 1.5 2007/01/05 22:18:52 pavalos Exp $ 39 */ 40 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 #include <errno.h> 47 #include <limits.h> 48 49 /* 50 * The cd and pwd commands. 51 */ 52 53 #include "shell.h" 54 #include "var.h" 55 #include "nodes.h" /* for jobs.h */ 56 #include "jobs.h" 57 #include "options.h" 58 #include "output.h" 59 #include "memalloc.h" 60 #include "error.h" 61 #include "exec.h" 62 #include "redir.h" 63 #include "mystring.h" 64 #include "show.h" 65 #include "cd.h" 66 67 STATIC int cdlogical(char *); 68 STATIC int cdphysical(char *); 69 STATIC int docd(char *, int, int); 70 STATIC char *getcomponent(void); 71 STATIC int updatepwd(char *); 72 73 STATIC char *curdir = NULL; /* current working directory */ 74 STATIC char *prevdir; /* previous working directory */ 75 STATIC char *cdcomppath; 76 77 int 78 cdcmd(int argc, char **argv) 79 { 80 const char *dest; 81 const char *path; 82 char *p; 83 struct stat statb; 84 int ch, phys, print = 0; 85 86 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 87 phys = Pflag; 88 while ((ch = getopt(argc, argv, "LP")) != -1) { 89 switch (ch) { 90 case 'L': 91 phys = 0; 92 break; 93 case 'P': 94 phys = 1; 95 break; 96 default: 97 error("unknown option: -%c", optopt); 98 break; 99 } 100 } 101 argc -= optind; 102 argv += optind; 103 104 if (argc > 1) 105 error("too many arguments"); 106 107 if ((dest = *argv) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 108 error("HOME not set"); 109 if (*dest == '\0') 110 dest = "."; 111 if (dest[0] == '-' && dest[1] == '\0') { 112 dest = prevdir ? prevdir : curdir; 113 if (dest) 114 print = 1; 115 else 116 dest = "."; 117 } 118 if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL) 119 path = nullstr; 120 while ((p = padvance(&path, dest)) != NULL) { 121 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { 122 if (!print) { 123 /* 124 * XXX - rethink 125 */ 126 if (p[0] == '.' && p[1] == '/' && p[2] != '\0') 127 print = strcmp(p + 2, dest); 128 else 129 print = strcmp(p, dest); 130 } 131 if (docd(p, print, phys) >= 0) 132 return 0; 133 } 134 } 135 error("can't cd to %s", dest); 136 /*NOTREACHED*/ 137 return 0; 138 } 139 140 141 /* 142 * Actually change the directory. In an interactive shell, print the 143 * directory name if "print" is nonzero. 144 */ 145 STATIC int 146 docd(char *dest, int print, int phys) 147 { 148 149 TRACE(("docd(\"%s\", %d, %d) called\n", dest, print, phys)); 150 151 /* If logical cd fails, fall back to physical. */ 152 if ((phys || cdlogical(dest) < 0) && cdphysical(dest) < 0) 153 return (-1); 154 155 if (print && iflag && curdir) 156 out1fmt("%s\n", curdir); 157 158 return 0; 159 } 160 161 STATIC int 162 cdlogical(char *dest) 163 { 164 char *p; 165 char *q; 166 char *component; 167 struct stat statb; 168 int first; 169 int badstat; 170 171 /* 172 * Check each component of the path. If we find a symlink or 173 * something we can't stat, clear curdir to force a getcwd() 174 * next time we get the value of the current directory. 175 */ 176 badstat = 0; 177 cdcomppath = stalloc(strlen(dest) + 1); 178 scopy(dest, cdcomppath); 179 STARTSTACKSTR(p); 180 if (*dest == '/') { 181 STPUTC('/', p); 182 cdcomppath++; 183 } 184 first = 1; 185 while ((q = getcomponent()) != NULL) { 186 if (q[0] == '\0' || (q[0] == '.' && q[1] == '\0')) 187 continue; 188 if (! first) 189 STPUTC('/', p); 190 first = 0; 191 component = q; 192 while (*q) 193 STPUTC(*q++, p); 194 if (equal(component, "..")) 195 continue; 196 STACKSTRNUL(p); 197 if (lstat(stackblock(), &statb) < 0) { 198 badstat = 1; 199 break; 200 } 201 } 202 203 INTOFF; 204 if (updatepwd(badstat ? NULL : dest) < 0 || chdir(curdir) < 0) { 205 INTON; 206 return (-1); 207 } 208 INTON; 209 return (0); 210 } 211 212 STATIC int 213 cdphysical(char *dest) 214 { 215 216 INTOFF; 217 if (chdir(dest) < 0 || updatepwd(NULL) < 0) { 218 INTON; 219 return (-1); 220 } 221 INTON; 222 return (0); 223 } 224 225 /* 226 * Get the next component of the path name pointed to by cdcomppath. 227 * This routine overwrites the string pointed to by cdcomppath. 228 */ 229 STATIC char * 230 getcomponent(void) 231 { 232 char *p; 233 char *start; 234 235 if ((p = cdcomppath) == NULL) 236 return NULL; 237 start = cdcomppath; 238 while (*p != '/' && *p != '\0') 239 p++; 240 if (*p == '\0') { 241 cdcomppath = NULL; 242 } else { 243 *p++ = '\0'; 244 cdcomppath = p; 245 } 246 return start; 247 } 248 249 250 /* 251 * Update curdir (the name of the current directory) in response to a 252 * cd command. We also call hashcd to let the routines in exec.c know 253 * that the current directory has changed. 254 */ 255 STATIC int 256 updatepwd(char *dir) 257 { 258 char *new; 259 char *p; 260 261 hashcd(); /* update command hash table */ 262 263 /* 264 * If our argument is NULL, we don't know the current directory 265 * any more because we traversed a symbolic link or something 266 * we couldn't stat(). 267 */ 268 if (dir == NULL || curdir == NULL) { 269 if (prevdir) 270 ckfree(prevdir); 271 INTOFF; 272 prevdir = curdir; 273 curdir = NULL; 274 if (getpwd() == NULL) { 275 INTON; 276 return (-1); 277 } 278 setvar("PWD", curdir, VEXPORT); 279 setvar("OLDPWD", prevdir, VEXPORT); 280 INTON; 281 return (0); 282 } 283 cdcomppath = stalloc(strlen(dir) + 1); 284 scopy(dir, cdcomppath); 285 STARTSTACKSTR(new); 286 if (*dir != '/') { 287 p = curdir; 288 while (*p) 289 STPUTC(*p++, new); 290 if (p[-1] == '/') 291 STUNPUTC(new); 292 } 293 while ((p = getcomponent()) != NULL) { 294 if (equal(p, "..")) { 295 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 296 } else if (*p != '\0' && ! equal(p, ".")) { 297 STPUTC('/', new); 298 while (*p) 299 STPUTC(*p++, new); 300 } 301 } 302 if (new == stackblock()) 303 STPUTC('/', new); 304 STACKSTRNUL(new); 305 INTOFF; 306 if (prevdir) 307 ckfree(prevdir); 308 prevdir = curdir; 309 curdir = savestr(stackblock()); 310 setvar("PWD", curdir, VEXPORT); 311 setvar("OLDPWD", prevdir, VEXPORT); 312 INTON; 313 314 return (0); 315 } 316 317 int 318 pwdcmd(int argc, char **argv) 319 { 320 char buf[PATH_MAX]; 321 int ch, phys; 322 323 optreset = 1; optind = 1; opterr = 0; /* initialize getopt */ 324 phys = Pflag; 325 while ((ch = getopt(argc, argv, "LP")) != -1) { 326 switch (ch) { 327 case 'L': 328 phys = 0; 329 break; 330 case 'P': 331 phys = 1; 332 break; 333 default: 334 error("unknown option: -%c", optopt); 335 break; 336 } 337 } 338 argc -= optind; 339 argv += optind; 340 341 if (argc != 0) 342 error("too many arguments"); 343 344 if (!phys && getpwd()) { 345 out1str(curdir); 346 out1c('\n'); 347 } else { 348 if (getcwd(buf, sizeof(buf)) == NULL) 349 error(".: %s", strerror(errno)); 350 out1str(buf); 351 out1c('\n'); 352 } 353 354 return 0; 355 } 356 357 /* 358 * Find out what the current directory is. If we already know the current 359 * directory, this routine returns immediately. 360 */ 361 char * 362 getpwd(void) 363 { 364 char buf[PATH_MAX]; 365 366 if (curdir) 367 return curdir; 368 if (getcwd(buf, sizeof(buf)) == NULL) { 369 char *pwd = getenv("PWD"); 370 struct stat stdot, stpwd; 371 372 if (pwd && *pwd == '/' && stat(".", &stdot) != -1 && 373 stat(pwd, &stpwd) != -1 && 374 stdot.st_dev == stpwd.st_dev && 375 stdot.st_ino == stpwd.st_ino) { 376 curdir = savestr(pwd); 377 return curdir; 378 } 379 return NULL; 380 } 381 curdir = savestr(buf); 382 383 return curdir; 384 } 385