158f0484fSRodney W. Grimes /* 29dc11641SPeter Wemm * Copyright (c) 1989, 1991, 1993, 1995 358f0484fSRodney W. Grimes * The Regents of the University of California. All rights reserved. 458f0484fSRodney W. Grimes * 558f0484fSRodney W. Grimes * Redistribution and use in source and binary forms, with or without 658f0484fSRodney W. Grimes * modification, are permitted provided that the following conditions 758f0484fSRodney W. Grimes * are met: 858f0484fSRodney W. Grimes * 1. Redistributions of source code must retain the above copyright 958f0484fSRodney W. Grimes * notice, this list of conditions and the following disclaimer. 1058f0484fSRodney W. Grimes * 2. Redistributions in binary form must reproduce the above copyright 1158f0484fSRodney W. Grimes * notice, this list of conditions and the following disclaimer in the 1258f0484fSRodney W. Grimes * documentation and/or other materials provided with the distribution. 1358f0484fSRodney W. Grimes * 3. All advertising materials mentioning features or use of this software 1458f0484fSRodney W. Grimes * must display the following acknowledgement: 1558f0484fSRodney W. Grimes * This product includes software developed by the University of 1658f0484fSRodney W. Grimes * California, Berkeley and its contributors. 1758f0484fSRodney W. Grimes * 4. Neither the name of the University nor the names of its contributors 1858f0484fSRodney W. Grimes * may be used to endorse or promote products derived from this software 1958f0484fSRodney W. Grimes * without specific prior written permission. 2058f0484fSRodney W. Grimes * 2158f0484fSRodney W. Grimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2258f0484fSRodney W. Grimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2358f0484fSRodney W. Grimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2458f0484fSRodney W. Grimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2558f0484fSRodney W. Grimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2658f0484fSRodney W. Grimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2758f0484fSRodney W. Grimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2858f0484fSRodney W. Grimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2958f0484fSRodney W. Grimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3058f0484fSRodney W. Grimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3158f0484fSRodney W. Grimes * SUCH DAMAGE. 3258f0484fSRodney W. Grimes */ 3358f0484fSRodney W. Grimes 3458f0484fSRodney W. Grimes #if defined(LIBC_SCCS) && !defined(lint) 359dc11641SPeter Wemm static char sccsid[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95"; 3658f0484fSRodney W. Grimes #endif /* LIBC_SCCS and not lint */ 3758f0484fSRodney W. Grimes 3858f0484fSRodney W. Grimes #include <sys/param.h> 3958f0484fSRodney W. Grimes #include <sys/stat.h> 4058f0484fSRodney W. Grimes 4158f0484fSRodney W. Grimes #include <dirent.h> 429dc11641SPeter Wemm #include <errno.h> 439dc11641SPeter Wemm #include <fcntl.h> 4458f0484fSRodney W. Grimes #include <stdio.h> 4558f0484fSRodney W. Grimes #include <stdlib.h> 4658f0484fSRodney W. Grimes #include <string.h> 4758f0484fSRodney W. Grimes #include <unistd.h> 48b7ecb08aSPeter Wemm #include <signal.h> 4958f0484fSRodney W. Grimes 5058f0484fSRodney W. Grimes #define ISDOT(dp) \ 5158f0484fSRodney W. Grimes (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \ 5251295a4dSJordan K. Hubbard (dp->d_name[1] == '.' && dp->d_name[2] == '\0'))) 5358f0484fSRodney W. Grimes 54b7ecb08aSPeter Wemm static int have__getcwd = 1; /* 0 = no, 1 = perhaps, 2 = yes */ 55b7ecb08aSPeter Wemm 5658f0484fSRodney W. Grimes char * 5758f0484fSRodney W. Grimes getcwd(pt, size) 5858f0484fSRodney W. Grimes char *pt; 5958f0484fSRodney W. Grimes size_t size; 6058f0484fSRodney W. Grimes { 6158f0484fSRodney W. Grimes register struct dirent *dp; 62f5f31fbaSDavid Greenman register DIR *dir = NULL; 6358f0484fSRodney W. Grimes register dev_t dev; 6458f0484fSRodney W. Grimes register ino_t ino; 6558f0484fSRodney W. Grimes register int first; 6658f0484fSRodney W. Grimes register char *bpt, *bup; 6758f0484fSRodney W. Grimes struct stat s; 6858f0484fSRodney W. Grimes dev_t root_dev; 6958f0484fSRodney W. Grimes ino_t root_ino; 7016be3810SDavid Greenman size_t ptsize, upsize; 7158f0484fSRodney W. Grimes int save_errno; 729c2d6fcfSPoul-Henning Kamp char *ept, *eup, *up, c; 7358f0484fSRodney W. Grimes 7458f0484fSRodney W. Grimes /* 7558f0484fSRodney W. Grimes * If no buffer specified by the user, allocate one as necessary. 7658f0484fSRodney W. Grimes * If a buffer is specified, the size has to be non-zero. The path 7758f0484fSRodney W. Grimes * is built from the end of the buffer backwards. 7858f0484fSRodney W. Grimes */ 7958f0484fSRodney W. Grimes if (pt) { 8058f0484fSRodney W. Grimes ptsize = 0; 8158f0484fSRodney W. Grimes if (!size) { 8258f0484fSRodney W. Grimes errno = EINVAL; 8358f0484fSRodney W. Grimes return (NULL); 8458f0484fSRodney W. Grimes } 85b01f0b7dSBruce Evans if (size == 1) { 86b01f0b7dSBruce Evans errno = ERANGE; 87b01f0b7dSBruce Evans return (NULL); 88b01f0b7dSBruce Evans } 8958f0484fSRodney W. Grimes ept = pt + size; 9058f0484fSRodney W. Grimes } else { 9158f0484fSRodney W. Grimes if ((pt = malloc(ptsize = 1024 - 4)) == NULL) 9258f0484fSRodney W. Grimes return (NULL); 9358f0484fSRodney W. Grimes ept = pt + ptsize; 9458f0484fSRodney W. Grimes } 95b7ecb08aSPeter Wemm if (have__getcwd) { 96b7ecb08aSPeter Wemm struct sigaction sa, osa; 97b7ecb08aSPeter Wemm int sigsys_installed = 0; 98b7ecb08aSPeter Wemm int ret; 99b7ecb08aSPeter Wemm 100b7ecb08aSPeter Wemm if (have__getcwd == 1) { /* unsure? */ 101b7ecb08aSPeter Wemm bzero(&sa, sizeof(sa)); 102b7ecb08aSPeter Wemm sa.sa_handler = SIG_IGN; 103b7ecb08aSPeter Wemm if (sigaction(SIGSYS, &sa, &osa) >= 0) 104b7ecb08aSPeter Wemm sigsys_installed = 1; 105b7ecb08aSPeter Wemm } 106b7ecb08aSPeter Wemm ret = __getcwd(pt, ept - pt); 107b7ecb08aSPeter Wemm if (sigsys_installed == 1) { 108b7ecb08aSPeter Wemm int oerrno = errno; 109b7ecb08aSPeter Wemm sigaction(SIGSYS, &osa, NULL); 110b7ecb08aSPeter Wemm errno = oerrno; 111b7ecb08aSPeter Wemm } 112b7ecb08aSPeter Wemm /* XXX a bogus syscall seems to return EINVAL(!) */ 113b7ecb08aSPeter Wemm if (ret < 0 && (errno == ENOSYS || errno == EINVAL)) 114b7ecb08aSPeter Wemm have__getcwd = 0; 115b7ecb08aSPeter Wemm else if (have__getcwd == 1) 116b7ecb08aSPeter Wemm have__getcwd = 2; /* yep, remember we have it */ 117b7ecb08aSPeter Wemm if (ret == 0) { 11836dff600SPoul-Henning Kamp if (*pt != '/') { 11927262cacSPoul-Henning Kamp bpt = pt; 12027262cacSPoul-Henning Kamp ept = pt + strlen(pt) - 1; 12127262cacSPoul-Henning Kamp while (bpt < ept) { 12227262cacSPoul-Henning Kamp c = *bpt; 12327262cacSPoul-Henning Kamp *bpt++ = *ept; 12427262cacSPoul-Henning Kamp *ept-- = c; 12527262cacSPoul-Henning Kamp } 12636dff600SPoul-Henning Kamp } 12727262cacSPoul-Henning Kamp return (pt); 12827262cacSPoul-Henning Kamp } 129b7ecb08aSPeter Wemm } 13058f0484fSRodney W. Grimes bpt = ept - 1; 13158f0484fSRodney W. Grimes *bpt = '\0'; 13258f0484fSRodney W. Grimes 13358f0484fSRodney W. Grimes /* 13458f0484fSRodney W. Grimes * Allocate bytes (1024 - malloc space) for the string of "../"'s. 13558f0484fSRodney W. Grimes * Should always be enough (it's 340 levels). If it's not, allocate 1369dc11641SPeter Wemm * as necessary. Special case the first stat, it's ".", not "..". 13758f0484fSRodney W. Grimes */ 13858f0484fSRodney W. Grimes if ((up = malloc(upsize = 1024 - 4)) == NULL) 13958f0484fSRodney W. Grimes goto err; 14058f0484fSRodney W. Grimes eup = up + MAXPATHLEN; 14158f0484fSRodney W. Grimes bup = up; 14258f0484fSRodney W. Grimes up[0] = '.'; 14358f0484fSRodney W. Grimes up[1] = '\0'; 14458f0484fSRodney W. Grimes 14558f0484fSRodney W. Grimes /* Save root values, so know when to stop. */ 14658f0484fSRodney W. Grimes if (stat("/", &s)) 14758f0484fSRodney W. Grimes goto err; 14858f0484fSRodney W. Grimes root_dev = s.st_dev; 14958f0484fSRodney W. Grimes root_ino = s.st_ino; 15058f0484fSRodney W. Grimes 15158f0484fSRodney W. Grimes errno = 0; /* XXX readdir has no error return. */ 15258f0484fSRodney W. Grimes 15358f0484fSRodney W. Grimes for (first = 1;; first = 0) { 15458f0484fSRodney W. Grimes /* Stat the current level. */ 15558f0484fSRodney W. Grimes if (lstat(up, &s)) 15658f0484fSRodney W. Grimes goto err; 15758f0484fSRodney W. Grimes 15858f0484fSRodney W. Grimes /* Save current node values. */ 15958f0484fSRodney W. Grimes ino = s.st_ino; 16058f0484fSRodney W. Grimes dev = s.st_dev; 16158f0484fSRodney W. Grimes 16258f0484fSRodney W. Grimes /* Check for reaching root. */ 16358f0484fSRodney W. Grimes if (root_dev == dev && root_ino == ino) { 16458f0484fSRodney W. Grimes *--bpt = '/'; 16558f0484fSRodney W. Grimes /* 16658f0484fSRodney W. Grimes * It's unclear that it's a requirement to copy the 16758f0484fSRodney W. Grimes * path to the beginning of the buffer, but it's always 16858f0484fSRodney W. Grimes * been that way and stuff would probably break. 16958f0484fSRodney W. Grimes */ 170e78bad23SJeffrey Hsu bcopy(bpt, pt, ept - bpt); 17158f0484fSRodney W. Grimes free(up); 17258f0484fSRodney W. Grimes return (pt); 17358f0484fSRodney W. Grimes } 17458f0484fSRodney W. Grimes 17558f0484fSRodney W. Grimes /* 17658f0484fSRodney W. Grimes * Build pointer to the parent directory, allocating memory 17758f0484fSRodney W. Grimes * as necessary. Max length is 3 for "../", the largest 17858f0484fSRodney W. Grimes * possible component name, plus a trailing NULL. 17958f0484fSRodney W. Grimes */ 18058f0484fSRodney W. Grimes if (bup + 3 + MAXNAMLEN + 1 >= eup) { 18158f0484fSRodney W. Grimes if ((up = realloc(up, upsize *= 2)) == NULL) 18258f0484fSRodney W. Grimes goto err; 18358f0484fSRodney W. Grimes bup = up; 18458f0484fSRodney W. Grimes eup = up + upsize; 18558f0484fSRodney W. Grimes } 18658f0484fSRodney W. Grimes *bup++ = '.'; 18758f0484fSRodney W. Grimes *bup++ = '.'; 18858f0484fSRodney W. Grimes *bup = '\0'; 18958f0484fSRodney W. Grimes 19058f0484fSRodney W. Grimes /* Open and stat parent directory. */ 19158f0484fSRodney W. Grimes if (!(dir = opendir(up)) || fstat(dirfd(dir), &s)) 19258f0484fSRodney W. Grimes goto err; 19358f0484fSRodney W. Grimes 19458f0484fSRodney W. Grimes /* Add trailing slash for next directory. */ 19558f0484fSRodney W. Grimes *bup++ = '/'; 1960d4453d3SPeter Wemm *bup = '\0'; 19758f0484fSRodney W. Grimes 19858f0484fSRodney W. Grimes /* 19958f0484fSRodney W. Grimes * If it's a mount point, have to stat each element because 20058f0484fSRodney W. Grimes * the inode number in the directory is for the entry in the 20158f0484fSRodney W. Grimes * parent directory, not the inode number of the mounted file. 20258f0484fSRodney W. Grimes */ 20358f0484fSRodney W. Grimes save_errno = 0; 20458f0484fSRodney W. Grimes if (s.st_dev == dev) { 20558f0484fSRodney W. Grimes for (;;) { 20658f0484fSRodney W. Grimes if (!(dp = readdir(dir))) 20758f0484fSRodney W. Grimes goto notfound; 20858f0484fSRodney W. Grimes if (dp->d_fileno == ino) 20958f0484fSRodney W. Grimes break; 21058f0484fSRodney W. Grimes } 21158f0484fSRodney W. Grimes } else 21258f0484fSRodney W. Grimes for (;;) { 21358f0484fSRodney W. Grimes if (!(dp = readdir(dir))) 21458f0484fSRodney W. Grimes goto notfound; 21558f0484fSRodney W. Grimes if (ISDOT(dp)) 21658f0484fSRodney W. Grimes continue; 21758f0484fSRodney W. Grimes bcopy(dp->d_name, bup, dp->d_namlen + 1); 21858f0484fSRodney W. Grimes 21958f0484fSRodney W. Grimes /* Save the first error for later. */ 22058f0484fSRodney W. Grimes if (lstat(up, &s)) { 22158f0484fSRodney W. Grimes if (!save_errno) 22258f0484fSRodney W. Grimes save_errno = errno; 22358f0484fSRodney W. Grimes errno = 0; 22458f0484fSRodney W. Grimes continue; 22558f0484fSRodney W. Grimes } 22658f0484fSRodney W. Grimes if (s.st_dev == dev && s.st_ino == ino) 22758f0484fSRodney W. Grimes break; 22858f0484fSRodney W. Grimes } 22958f0484fSRodney W. Grimes 23058f0484fSRodney W. Grimes /* 23158f0484fSRodney W. Grimes * Check for length of the current name, preceding slash, 23258f0484fSRodney W. Grimes * leading slash. 23358f0484fSRodney W. Grimes */ 234b01f0b7dSBruce Evans if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) { 23558f0484fSRodney W. Grimes size_t len, off; 23658f0484fSRodney W. Grimes 23758f0484fSRodney W. Grimes if (!ptsize) { 23858f0484fSRodney W. Grimes errno = ERANGE; 23958f0484fSRodney W. Grimes goto err; 24058f0484fSRodney W. Grimes } 24158f0484fSRodney W. Grimes off = bpt - pt; 24258f0484fSRodney W. Grimes len = ept - bpt; 24358f0484fSRodney W. Grimes if ((pt = realloc(pt, ptsize *= 2)) == NULL) 24458f0484fSRodney W. Grimes goto err; 24558f0484fSRodney W. Grimes bpt = pt + off; 24658f0484fSRodney W. Grimes ept = pt + ptsize; 247e78bad23SJeffrey Hsu bcopy(bpt, ept - len, len); 24858f0484fSRodney W. Grimes bpt = ept - len; 24958f0484fSRodney W. Grimes } 25058f0484fSRodney W. Grimes if (!first) 25158f0484fSRodney W. Grimes *--bpt = '/'; 25258f0484fSRodney W. Grimes bpt -= dp->d_namlen; 25358f0484fSRodney W. Grimes bcopy(dp->d_name, bpt, dp->d_namlen); 25458f0484fSRodney W. Grimes (void) closedir(dir); 255f5f31fbaSDavid Greenman dir = NULL; 25658f0484fSRodney W. Grimes 25758f0484fSRodney W. Grimes /* Truncate any file name. */ 25858f0484fSRodney W. Grimes *bup = '\0'; 25958f0484fSRodney W. Grimes } 26058f0484fSRodney W. Grimes 26158f0484fSRodney W. Grimes notfound: 26258f0484fSRodney W. Grimes /* 26358f0484fSRodney W. Grimes * If readdir set errno, use it, not any saved error; otherwise, 26458f0484fSRodney W. Grimes * didn't find the current directory in its parent directory, set 26558f0484fSRodney W. Grimes * errno to ENOENT. 26658f0484fSRodney W. Grimes */ 26758f0484fSRodney W. Grimes if (!errno) 26858f0484fSRodney W. Grimes errno = save_errno ? save_errno : ENOENT; 26958f0484fSRodney W. Grimes /* FALLTHROUGH */ 27058f0484fSRodney W. Grimes err: 2714773010dSStephen McKay save_errno = errno; 2724773010dSStephen McKay 27358f0484fSRodney W. Grimes if (ptsize) 27458f0484fSRodney W. Grimes free(pt); 275f5f31fbaSDavid Greenman if (dir) 276f5f31fbaSDavid Greenman (void) closedir(dir); 27758f0484fSRodney W. Grimes free(up); 2784773010dSStephen McKay 2794773010dSStephen McKay errno = save_errno; 28058f0484fSRodney W. Grimes return (NULL); 28158f0484fSRodney W. Grimes } 282