cd.c revision 25222
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 * $Id: cd.c,v 1.14 1997/02/22 13:58:22 peter Exp $ 37 */ 38 39#ifndef lint 40static char const sccsid[] = "@(#)cd.c 8.2 (Berkeley) 5/4/95"; 41#endif /* not lint */ 42 43#include <sys/types.h> 44#include <sys/stat.h> 45#include <stdlib.h> 46#include <string.h> 47#include <unistd.h> 48#include <errno.h> 49 50/* 51 * The cd and pwd commands. 52 */ 53 54#include "shell.h" 55#include "var.h" 56#include "nodes.h" /* for jobs.h */ 57#include "jobs.h" 58#include "options.h" 59#include "output.h" 60#include "memalloc.h" 61#include "error.h" 62#include "exec.h" 63#include "redir.h" 64#include "mystring.h" 65#include "show.h" 66#include "cd.h" 67 68STATIC int docd __P((char *, int)); 69STATIC char *getcomponent __P((void)); 70STATIC void updatepwd __P((char *)); 71 72char *curdir = NULL; /* current working directory */ 73char *prevdir; /* previous working directory */ 74STATIC char *cdcomppath; 75 76int 77cdcmd(argc, argv) 78 int argc; 79 char **argv; 80{ 81 char *dest; 82 char *path; 83 char *p; 84 struct stat statb; 85 int print = 0; 86 87 nextopt(nullstr); 88 if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL) 89 error("HOME not set"); 90 if (*dest == '\0') 91 dest = "."; 92 if (dest[0] == '-' && dest[1] == '\0') { 93 dest = prevdir ? prevdir : curdir; 94 if (dest) 95 print = 1; 96 else 97 dest = "."; 98 } 99 if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL) 100 path = nullstr; 101 while ((p = padvance(&path, dest)) != NULL) { 102 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { 103 if (!print) { 104 /* 105 * XXX - rethink 106 */ 107 if (p[0] == '.' && p[1] == '/') 108 p += 2; 109 print = strcmp(p, dest); 110 } 111 if (docd(p, print) >= 0) 112 return 0; 113 114 } 115 } 116 error("can't cd to %s", dest); 117 /*NOTREACHED*/ 118 return 0; 119} 120 121 122/* 123 * Actually do the chdir. In an interactive shell, print the 124 * directory name if "print" is nonzero. 125 */ 126STATIC int 127docd(dest, print) 128 char *dest; 129 int print; 130{ 131 132 TRACE(("docd(\"%s\", %d) called\n", dest, print)); 133 INTOFF; 134 updatepwd(dest); 135 if (chdir(stackblock()) < 0) { 136 INTON; 137 return -1; 138 } 139 hashcd(); /* update command hash table */ 140 if (prevdir) 141 ckfree(prevdir); 142 prevdir = curdir; 143 curdir = savestr(stackblock()); 144 INTON; 145 if (print && iflag) 146 out1fmt("%s\n", stackblock()); 147 return 0; 148} 149 150 151/* 152 * Get the next component of the path name pointed to by cdcomppath. 153 * This routine overwrites the string pointed to by cdcomppath. 154 */ 155STATIC char * 156getcomponent() 157{ 158 char *p; 159 char *start; 160 161 if ((p = cdcomppath) == NULL) 162 return NULL; 163 start = cdcomppath; 164 while (*p != '/' && *p != '\0') 165 p++; 166 if (*p == '\0') { 167 cdcomppath = NULL; 168 } else { 169 *p++ = '\0'; 170 cdcomppath = p; 171 } 172 return start; 173} 174 175 176/* 177 * Determine the new working directory, but don't actually enforce 178 * any changes. 179 */ 180STATIC void 181updatepwd(dir) 182 char *dir; 183{ 184 char *new; 185 char *p; 186 187 cdcomppath = stalloc(strlen(dir) + 1); 188 scopy(dir, cdcomppath); 189 STARTSTACKSTR(new); 190 if (*dir != '/') { 191 if (curdir == NULL) 192 return; 193 p = curdir; 194 while (*p) 195 STPUTC(*p++, new); 196 if (p[-1] == '/') 197 STUNPUTC(new); 198 } 199 while ((p = getcomponent()) != NULL) { 200 if (equal(p, "..")) { 201 while (new > stackblock() && (STUNPUTC(new), *new) != '/'); 202 } else if (*p != '\0' && ! equal(p, ".")) { 203 STPUTC('/', new); 204 while (*p) 205 STPUTC(*p++, new); 206 } 207 } 208 if (new == stackblock()) 209 STPUTC('/', new); 210 STACKSTRNUL(new); 211} 212 213 214int 215pwdcmd(argc, argv) 216 int argc; 217 char **argv; 218{ 219 if (!getpwd()) 220 error("getcwd() failed: %s", strerror(errno)); 221 out1str(curdir); 222 out1c('\n'); 223 return 0; 224} 225 226 227/* 228 * Find out what the current directory is. If we already know the current 229 * directory, this routine returns immediately. 230 */ 231char * 232getpwd() 233{ 234 if (curdir) 235 return (curdir); 236 return ((curdir = getcwd(NULL, 0))); 237} 238