cd.c revision 1.12
1 /* $NetBSD: cd.c,v 1.12 1995/03/21 09:08:48 cgd Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifndef lint 40 #if 0 41 static char sccsid[] = "@(#)cd.c 8.1 (Berkeley) 5/31/93"; 42 #else 43 static char rcsid[] = "$NetBSD: cd.c,v 1.12 1995/03/21 09:08:48 cgd Exp $"; 44 #endif 45 #endif /* not lint */ 46 47 #include <sys/types.h> 48 #include <sys/stat.h> 49 #include <unistd.h> 50 #include <errno.h> 51 52 /* 53 * The cd and pwd commands. 54 */ 55 56 #include "shell.h" 57 #include "var.h" 58 #include "nodes.h" /* for jobs.h */ 59 #include "jobs.h" 60 #include "options.h" 61 #include "output.h" 62 #include "memalloc.h" 63 #include "error.h" 64 #include "mystring.h" 65 #include "extern.h" 66 67 68 #ifdef __STDC__ 69 STATIC int docd(char *, int); 70 STATIC void updatepwd(char *); 71 STATIC void getpwd(void); 72 STATIC char *getcomponent(void); 73 #else 74 STATIC int docd(); 75 STATIC void updatepwd(); 76 STATIC void getpwd(); 77 STATIC char *getcomponent(); 78 #endif 79 80 81 char *curdir; /* current working directory */ 82 char *prevdir; /* previous working directory */ 83 STATIC char *cdcomppath; 84 85 int 86 cdcmd(argc, argv) 87 int argc; 88 char **argv; 89 { 90 char *dest; 91 char *path; 92 char *p; 93 struct stat statb; 94 char *padvance(); 95 int print = 0; 96 97 nextopt(nullstr); 98 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 99 error("HOME not set"); 100 if (dest[0] == '-' && dest[1] == '\0') { 101 dest = prevdir ? prevdir : curdir; 102 print = 1; 103 } 104 if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL) 105 path = nullstr; 106 while ((p = padvance(&path, dest)) != NULL) { 107 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { 108 if (!print) { 109 /* 110 * XXX - rethink 111 */ 112 if (p[0] == '.' && p[1] == '/') 113 p += 2; 114 print = strcmp(p, dest); 115 } 116 if (docd(p, print) >= 0) 117 return 0; 118 119 } 120 } 121 error("can't cd to %s", dest); 122 } 123 124 125 /* 126 * Actually do the chdir. If the name refers to symbolic links, we 127 * compute the actual directory name before doing the cd. In an 128 * interactive shell, print the directory name if "print" is nonzero 129 * or if the name refers to a symbolic link. We also print the name 130 * if "/u/logname" was expanded in it, since this is similar to a 131 * symbolic link. (The check for this breaks if the user gives the 132 * cd command some additional, unused arguments.) 133 */ 134 135 #if SYMLINKS == 0 136 STATIC int 137 docd(dest, print) 138 char *dest; 139 { 140 INTOFF; 141 if (chdir(dest) < 0) { 142 INTON; 143 return -1; 144 } 145 updatepwd(dest); 146 INTON; 147 if (print && iflag) 148 out1fmt("%s\n", stackblock()); 149 return 0; 150 } 151 152 #else 153 154 155 156 STATIC int 157 docd(dest, print) 158 char *dest; 159 int print; 160 { 161 register char *p; 162 register char *q; 163 char *symlink; 164 char *component; 165 struct stat statb; 166 int first; 167 int i; 168 169 TRACE(("docd(\"%s\", %d) called\n", dest, print)); 170 171 top: 172 cdcomppath = dest; 173 STARTSTACKSTR(p); 174 if (*dest == '/') { 175 STPUTC('/', p); 176 cdcomppath++; 177 } 178 first = 1; 179 while ((q = getcomponent()) != NULL) { 180 if (q[0] == '\0' || q[0] == '.' && q[1] == '\0') 181 continue; 182 if (! first) 183 STPUTC('/', p); 184 first = 0; 185 component = q; 186 while (*q) 187 STPUTC(*q++, p); 188 if (equal(component, "..")) 189 continue; 190 STACKSTRNUL(p); 191 if (lstat(stackblock(), &statb) < 0) 192 error("lstat %s failed", stackblock()); 193 if (!S_ISLNK(statb.st_mode)) 194 continue; 195 196 /* Hit a symbolic link. We have to start all over again. */ 197 print = 1; 198 STPUTC('\0', p); 199 symlink = grabstackstr(p); 200 i = (int)statb.st_size + 2; /* 2 for '/' and '\0' */ 201 if (cdcomppath != NULL) 202 i += strlen(cdcomppath); 203 p = stalloc(i); 204 if (readlink(symlink, p, (int)statb.st_size) < 0) { 205 error("readlink %s failed", stackblock()); 206 } 207 if (cdcomppath != NULL) { 208 p[(int)statb.st_size] = '/'; 209 scopy(cdcomppath, p + (int)statb.st_size + 1); 210 } else { 211 p[(int)statb.st_size] = '\0'; 212 } 213 if (p[0] != '/') { /* relative path name */ 214 char *r; 215 q = r = symlink; 216 while (*q) { 217 if (*q++ == '/') 218 r = q; 219 } 220 *r = '\0'; 221 dest = stalloc(strlen(symlink) + strlen(p) + 1); 222 scopy(symlink, dest); 223 strcat(dest, p); 224 } else { 225 dest = p; 226 } 227 goto top; 228 } 229 STPUTC('\0', p); 230 p = grabstackstr(p); 231 INTOFF; 232 if (chdir(p) < 0) { 233 INTON; 234 return -1; 235 } 236 updatepwd(p); 237 INTON; 238 if (print && iflag) 239 out1fmt("%s\n", p); 240 return 0; 241 } 242 #endif /* SYMLINKS */ 243 244 245 246 /* 247 * Get the next component of the path name pointed to by cdcomppath. 248 * This routine overwrites the string pointed to by cdcomppath. 249 */ 250 251 STATIC char * 252 getcomponent() { 253 register char *p; 254 char *start; 255 256 if ((p = cdcomppath) == NULL) 257 return NULL; 258 start = cdcomppath; 259 while (*p != '/' && *p != '\0') 260 p++; 261 if (*p == '\0') { 262 cdcomppath = NULL; 263 } else { 264 *p++ = '\0'; 265 cdcomppath = p; 266 } 267 return start; 268 } 269 270 271 272 /* 273 * Update curdir (the name of the current directory) in response to a 274 * cd command. We also call hashcd to let the routines in exec.c know 275 * that the current directory has changed. 276 */ 277 278 void hashcd(); 279 280 STATIC void 281 updatepwd(dir) 282 char *dir; 283 { 284 char *new; 285 char *p; 286 287 hashcd(); /* update command hash table */ 288 cdcomppath = stalloc(strlen(dir) + 1); 289 scopy(dir, cdcomppath); 290 STARTSTACKSTR(new); 291 if (*dir != '/') { 292 if (curdir == NULL) 293 return; 294 p = curdir; 295 while (*p) 296 STPUTC(*p++, new); 297 if (p[-1] == '/') 298 STUNPUTC(new); 299 } 300 while ((p = getcomponent()) != NULL) { 301 if (equal(p, "..")) { 302 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 303 } else if (*p != '\0' && ! equal(p, ".")) { 304 STPUTC('/', new); 305 while (*p) 306 STPUTC(*p++, new); 307 } 308 } 309 if (new == stackblock()) 310 STPUTC('/', new); 311 STACKSTRNUL(new); 312 INTOFF; 313 if (prevdir) 314 ckfree(prevdir); 315 prevdir = curdir; 316 curdir = savestr(stackblock()); 317 INTON; 318 } 319 320 321 322 int 323 pwdcmd(argc, argv) 324 int argc; 325 char **argv; 326 { 327 getpwd(); 328 out1str(curdir); 329 out1c('\n'); 330 return 0; 331 } 332 333 334 335 /* 336 * Run /bin/pwd to find out what the current directory is. We suppress 337 * interrupts throughout most of this, but the user can still break out 338 * of it by killing the pwd program. If we already know the current 339 * directory, this routine returns immediately. 340 */ 341 342 #define MAXPWD 256 343 344 STATIC void 345 getpwd() { 346 char buf[MAXPWD]; 347 char *p; 348 int i; 349 int status; 350 struct job *jp; 351 int pip[2]; 352 353 if (curdir) 354 return; 355 INTOFF; 356 if (pipe(pip) < 0) 357 error("Pipe call failed"); 358 jp = makejob((union node *)NULL, 1); 359 if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) { 360 close(pip[0]); 361 if (pip[1] != 1) { 362 close(1); 363 copyfd(pip[1], 1); 364 close(pip[1]); 365 } 366 execl("/bin/pwd", "pwd", (char *)0); 367 error("Cannot exec /bin/pwd"); 368 } 369 close(pip[1]); 370 pip[1] = -1; 371 p = buf; 372 while ((i = read(pip[0], p, buf + MAXPWD - p)) > 0 373 || i == -1 && errno == EINTR) { 374 if (i > 0) 375 p += i; 376 } 377 close(pip[0]); 378 pip[0] = -1; 379 status = waitforjob(jp); 380 if (status != 0) 381 error((char *)0); 382 if (i < 0 || p == buf || p[-1] != '\n') 383 error("pwd command failed"); 384 p[-1] = '\0'; 385 curdir = savestr(buf); 386 INTON; 387 } 388
Indexes created Mon Sep 29 13:09:55 GMT 2025