[BACK]Return to getcwd.c CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / lib / libc / gen

Annotation of src/lib/libc/gen/getcwd.c, Revision 1.32

1.32    ! agc         1: /*     $NetBSD: getcwd.c,v 1.31 2003/08/03 04:35:50 itojun Exp $       */
1.4       cgd         2:
1.1       cgd         3: /*
1.8       perry       4:  * Copyright (c) 1989, 1991, 1993, 1995
1.4       cgd         5:  *     The Regents of the University of California.  All rights reserved.
1.1       cgd         6:  *
1.8       perry       7:  * This code is derived from software contributed to Berkeley by
                      8:  * Jan-Simon Pendry.
                      9:  *
1.1       cgd        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.
1.32    ! agc        18:  * 3. Neither the name of the University nor the names of its contributors
1.1       cgd        19:  *    may be used to endorse or promote products derived from this software
                     20:  *    without specific prior written permission.
                     21:  *
                     22:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     23:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     24:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     25:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     26:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     27:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     28:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     29:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     30:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     31:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     32:  * SUCH DAMAGE.
                     33:  */
                     34:
1.6       christos   35: #include <sys/cdefs.h>
1.1       cgd        36: #if defined(LIBC_SCCS) && !defined(lint)
1.4       cgd        37: #if 0
1.8       perry      38: static char sccsid[] = "@(#)getcwd.c   8.5 (Berkeley) 2/7/95";
1.4       cgd        39: #else
1.32    ! agc        40: __RCSID("$NetBSD: getcwd.c,v 1.31 2003/08/03 04:35:50 itojun Exp $");
1.4       cgd        41: #endif
1.1       cgd        42: #endif /* LIBC_SCCS and not lint */
                     43:
1.7       jtc        44: #include "namespace.h"
1.1       cgd        45: #include <sys/param.h>
                     46: #include <sys/stat.h>
1.8       perry      47:
1.22      lukem      48: #include <assert.h>
1.8       perry      49: #include <dirent.h>
1.1       cgd        50: #include <errno.h>
1.8       perry      51: #include <fcntl.h>
1.1       cgd        52: #include <stdio.h>
                     53: #include <stdlib.h>
                     54: #include <string.h>
                     55: #include <unistd.h>
1.17      sommerfe   56:
                     57: #include "extern.h"
1.7       jtc        58:
                     59: #ifdef __weak_alias
1.24      mycroft    60: __weak_alias(getcwd,_getcwd)
                     61: __weak_alias(realpath,_realpath)
1.7       jtc        62: #endif
1.1       cgd        63:
                     64: #define        ISDOT(dp) \
                     65:        (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
1.6       christos   66:            (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
1.1       cgd        67:
1.8       perry      68:
1.15      christos   69: #if defined(__SVR4) || defined(__svr4__)
                     70: #define d_fileno d_ino
                     71: #endif
                     72:
1.8       perry      73: /*
                     74:  * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
                     75:  *
                     76:  * Find the real name of path, by removing all ".", ".." and symlink
                     77:  * components.  Returns (resolved) on success, or (NULL) on failure,
                     78:  * in which case the path which caused trouble is left in (resolved).
                     79:  */
                     80: char *
                     81: realpath(path, resolved)
                     82:        const char *path;
                     83:        char *resolved;
                     84: {
                     85:        struct stat sb;
1.21      fvdl       86:        int fd, n, rootd, serrno, nlnk = 0;
1.8       perry      87:        char *p, *q, wbuf[MAXPATHLEN];
1.22      lukem      88:
                     89:        _DIAGASSERT(path != NULL);
                     90:        _DIAGASSERT(resolved != NULL);
1.8       perry      91:
                     92:        /* Save the starting point. */
                     93:        if ((fd = open(".", O_RDONLY)) < 0) {
1.28      itojun     94:                (void)strlcpy(resolved, ".", MAXPATHLEN);
1.8       perry      95:                return (NULL);
                     96:        }
                     97:
                     98:        /*
                     99:         * Find the dirname and basename from the path to be resolved.
                    100:         * Change directory to the dirname component.
                    101:         * lstat the basename part.
                    102:         *     if it is a symlink, read in the value and loop.
                    103:         *     if it is a directory, then change to that directory.
                    104:         * get the current directory name and append the basename.
                    105:         */
1.31      itojun    106:        if (strlcpy(resolved, path, MAXPATHLEN) >= MAXPATHLEN) {
                    107:                errno = ENAMETOOLONG;
                    108:                goto err1;
                    109:        }
1.8       perry     110: loop:
                    111:        q = strrchr(resolved, '/');
                    112:        if (q != NULL) {
                    113:                p = q + 1;
                    114:                if (q == resolved)
                    115:                        q = "/";
                    116:                else {
                    117:                        do {
                    118:                                --q;
                    119:                        } while (q > resolved && *q == '/');
                    120:                        q[1] = '\0';
                    121:                        q = resolved;
                    122:                }
                    123:                if (chdir(q) < 0)
                    124:                        goto err1;
                    125:        } else
                    126:                p = resolved;
                    127:
                    128:        /* Deal with the last component. */
                    129:        if (lstat(p, &sb) == 0) {
                    130:                if (S_ISLNK(sb.st_mode)) {
1.21      fvdl      131:                        if (nlnk++ >= MAXSYMLINKS) {
                    132:                                errno = ELOOP;
                    133:                                goto err1;
                    134:                        }
1.26      provos    135:                        n = readlink(p, resolved, MAXPATHLEN-1);
1.8       perry     136:                        if (n < 0)
                    137:                                goto err1;
                    138:                        resolved[n] = '\0';
                    139:                        goto loop;
                    140:                }
                    141:                if (S_ISDIR(sb.st_mode)) {
                    142:                        if (chdir(p) < 0)
                    143:                                goto err1;
                    144:                        p = "";
                    145:                }
                    146:        }
                    147:
                    148:        /*
                    149:         * Save the last component name and get the full pathname of
                    150:         * the current directory.
                    151:         */
1.31      itojun    152:        if (strlcpy(wbuf, p, sizeof(wbuf)) >= sizeof(wbuf)) {
                    153:                errno = ENAMETOOLONG;
                    154:                goto err1;
                    155:        }
1.8       perry     156:
                    157:        /*
                    158:         * Call the inernal internal version of getcwd which
                    159:         * does a physical search rather than using the $PWD short-cut
                    160:         */
1.12      lukem     161:        if (getcwd(resolved, MAXPATHLEN) == 0)
1.8       perry     162:                goto err1;
                    163:
                    164:        /*
                    165:         * Join the two strings together, ensuring that the right thing
                    166:         * happens if the last component is empty, or the dirname is root.
                    167:         */
                    168:        if (resolved[0] == '/' && resolved[1] == '\0')
                    169:                rootd = 1;
                    170:        else
                    171:                rootd = 0;
                    172:
                    173:        if (*wbuf) {
1.29      itojun    174:                if (strlen(resolved) + strlen(wbuf) + (rootd ? 0 : 1) + 1 >
                    175:                    MAXPATHLEN) {
1.8       perry     176:                        errno = ENAMETOOLONG;
                    177:                        goto err1;
                    178:                }
                    179:                if (rootd == 0)
1.31      itojun    180:                        if (strlcat(resolved, "/", MAXPATHLEN) >= MAXPATHLEN) {
                    181:                                errno = ENAMETOOLONG;
                    182:                                goto err1;
                    183:                        }
                    184:                if (strlcat(resolved, wbuf, MAXPATHLEN) >= MAXPATHLEN) {
                    185:                        errno = ENAMETOOLONG;
                    186:                        goto err1;
                    187:                }
1.8       perry     188:        }
                    189:
                    190:        /* Go back to where we came from. */
                    191:        if (fchdir(fd) < 0) {
                    192:                serrno = errno;
                    193:                goto err2;
                    194:        }
                    195:
                    196:        /* It's okay if the close fails, what's an fd more or less? */
                    197:        (void)close(fd);
                    198:        return (resolved);
                    199:
                    200: err1:  serrno = errno;
                    201:        (void)fchdir(fd);
                    202: err2:  (void)close(fd);
                    203:        errno = serrno;
                    204:        return (NULL);
                    205: }
                    206:
1.16      sommerfe  207: #ifdef OLD_GETCWD
                    208:
1.12      lukem     209: char *
                    210: getcwd(pt, size)
1.8       perry     211:        char *pt;
                    212:        size_t size;
                    213: {
1.10      perry     214:        struct dirent *dp;
                    215:        DIR *dir;
                    216:        dev_t dev;
                    217:        ino_t ino;
                    218:        int first;
                    219:        char *bpt, *bup;
1.1       cgd       220:        struct stat s;
                    221:        dev_t root_dev;
                    222:        ino_t root_ino;
                    223:        size_t ptsize, upsize;
                    224:        int save_errno;
                    225:        char *ept, *eup, *up;
1.15      christos  226:        size_t dlen;
1.1       cgd       227:
                    228:        /*
                    229:         * If no buffer specified by the user, allocate one as necessary.
                    230:         * If a buffer is specified, the size has to be non-zero.  The path
                    231:         * is built from the end of the buffer backwards.
                    232:         */
                    233:        if (pt) {
                    234:                ptsize = 0;
                    235:                if (!size) {
                    236:                        errno = EINVAL;
1.4       cgd       237:                        return (NULL);
1.1       cgd       238:                }
                    239:                ept = pt + size;
                    240:        } else {
1.4       cgd       241:                if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
                    242:                        return (NULL);
1.1       cgd       243:                ept = pt + ptsize;
                    244:        }
                    245:        bpt = ept - 1;
                    246:        *bpt = '\0';
                    247:
                    248:        /*
                    249:         * Allocate bytes (1024 - malloc space) for the string of "../"'s.
                    250:         * Should always be enough (it's 340 levels).  If it's not, allocate
1.8       perry     251:         * as necessary.  Special case the first stat, it's ".", not "..".
1.1       cgd       252:         */
1.4       cgd       253:        if ((up = malloc(upsize = 1024 - 4)) == NULL)
1.1       cgd       254:                goto err;
                    255:        eup = up + MAXPATHLEN;
                    256:        bup = up;
                    257:        up[0] = '.';
                    258:        up[1] = '\0';
                    259:
                    260:        /* Save root values, so know when to stop. */
                    261:        if (stat("/", &s))
                    262:                goto err;
                    263:        root_dev = s.st_dev;
                    264:        root_ino = s.st_ino;
                    265:
                    266:        errno = 0;                      /* XXX readdir has no error return. */
                    267:
                    268:        for (first = 1;; first = 0) {
                    269:                /* Stat the current level. */
                    270:                if (lstat(up, &s))
                    271:                        goto err;
                    272:
                    273:                /* Save current node values. */
                    274:                ino = s.st_ino;
                    275:                dev = s.st_dev;
                    276:
                    277:                /* Check for reaching root. */
                    278:                if (root_dev == dev && root_ino == ino) {
                    279:                        *--bpt = '/';
                    280:                        /*
                    281:                         * It's unclear that it's a requirement to copy the
                    282:                         * path to the beginning of the buffer, but it's always
                    283:                         * been that way and stuff would probably break.
                    284:                         */
1.14      perry     285:                        memmove(pt, bpt,  (size_t)(ept - bpt));
1.1       cgd       286:                        free(up);
1.4       cgd       287:                        return (pt);
1.1       cgd       288:                }
                    289:
                    290:                /*
                    291:                 * Build pointer to the parent directory, allocating memory
                    292:                 * as necessary.  Max length is 3 for "../", the largest
                    293:                 * possible component name, plus a trailing NULL.
                    294:                 */
                    295:                if (bup + 3  + MAXNAMLEN + 1 >= eup) {
1.4       cgd       296:                        if ((up = realloc(up, upsize *= 2)) == NULL)
1.1       cgd       297:                                goto err;
1.4       cgd       298:                        bup = up;
1.1       cgd       299:                        eup = up + upsize;
                    300:                }
                    301:                *bup++ = '.';
                    302:                *bup++ = '.';
                    303:                *bup = '\0';
                    304:
                    305:                /* Open and stat parent directory. */
                    306:                if (!(dir = opendir(up)) || fstat(dirfd(dir), &s))
                    307:                        goto err;
                    308:
                    309:                /* Add trailing slash for next directory. */
                    310:                *bup++ = '/';
                    311:
                    312:                /*
                    313:                 * If it's a mount point, have to stat each element because
                    314:                 * the inode number in the directory is for the entry in the
                    315:                 * parent directory, not the inode number of the mounted file.
                    316:                 */
                    317:                save_errno = 0;
                    318:                if (s.st_dev == dev) {
                    319:                        for (;;) {
                    320:                                if (!(dp = readdir(dir)))
                    321:                                        goto notfound;
1.15      christos  322:                                if (dp->d_fileno == ino) {
1.19      christos  323: #if defined(__SVR4) || defined(__svr4__) || defined(__linux__)
1.15      christos  324:                                        dlen = strlen(dp->d_name);
                    325: #else
                    326:                                        dlen = dp->d_namlen;
                    327: #endif
1.1       cgd       328:                                        break;
1.15      christos  329:                                }
1.1       cgd       330:                        }
                    331:                } else
                    332:                        for (;;) {
                    333:                                if (!(dp = readdir(dir)))
                    334:                                        goto notfound;
                    335:                                if (ISDOT(dp))
                    336:                                        continue;
1.19      christos  337: #if defined(__SVR4) || defined(__svr4__) || defined(__linux__)
1.15      christos  338:                                dlen = strlen(dp->d_name);
                    339: #else
                    340:                                dlen = dp->d_namlen;
                    341: #endif
                    342:                                memmove(bup, dp->d_name, dlen + 1);
1.1       cgd       343:
                    344:                                /* Save the first error for later. */
                    345:                                if (lstat(up, &s)) {
                    346:                                        if (!save_errno)
                    347:                                                save_errno = errno;
                    348:                                        errno = 0;
                    349:                                        continue;
                    350:                                }
                    351:                                if (s.st_dev == dev && s.st_ino == ino)
                    352:                                        break;
                    353:                        }
                    354:
                    355:                /*
                    356:                 * Check for length of the current name, preceding slash,
                    357:                 * leading slash.
                    358:                 */
1.15      christos  359:                if (bpt - pt <= dlen + (first ? 1 : 2)) {
1.1       cgd       360:                        size_t len, off;
                    361:
                    362:                        if (!ptsize) {
                    363:                                errno = ERANGE;
                    364:                                goto err;
                    365:                        }
                    366:                        off = bpt - pt;
                    367:                        len = ept - bpt;
1.4       cgd       368:                        if ((pt = realloc(pt, ptsize *= 2)) == NULL)
1.1       cgd       369:                                goto err;
                    370:                        bpt = pt + off;
                    371:                        ept = pt + ptsize;
1.14      perry     372:                        memmove(ept - len, bpt, len);
1.1       cgd       373:                        bpt = ept - len;
                    374:                }
                    375:                if (!first)
                    376:                        *--bpt = '/';
1.15      christos  377:                bpt -= dlen;
                    378:                memmove(bpt, dp->d_name, dlen);
1.1       cgd       379:                (void)closedir(dir);
                    380:
                    381:                /* Truncate any file name. */
                    382:                *bup = '\0';
                    383:        }
                    384:
                    385: notfound:
                    386:        /*
                    387:         * If readdir set errno, use it, not any saved error; otherwise,
                    388:         * didn't find the current directory in its parent directory, set
                    389:         * errno to ENOENT.
                    390:         */
                    391:        if (!errno)
                    392:                errno = save_errno ? save_errno : ENOENT;
                    393:        /* FALLTHROUGH */
                    394: err:
                    395:        if (ptsize)
                    396:                free(pt);
                    397:        free(up);
1.4       cgd       398:        return (NULL);
1.1       cgd       399: }
1.16      sommerfe  400:
                    401: #else /* New getcwd */
                    402:
                    403: char *
                    404: getcwd(pt, size)
                    405:        char *pt;
                    406:        size_t size;
                    407: {
1.18      christos  408:        size_t ptsize, bufsize;
                    409:        int len;
1.16      sommerfe  410:
                    411:        /*
                    412:         * If no buffer specified by the user, allocate one as necessary.
                    413:         * If a buffer is specified, the size has to be non-zero.  The path
                    414:         * is built from the end of the buffer backwards.
                    415:         */
                    416:        if (pt) {
                    417:                ptsize = 0;
                    418:                if (!size) {
                    419:                        errno = EINVAL;
                    420:                        return (NULL);
                    421:                }
                    422:                bufsize = size;
                    423:        } else {
                    424:                if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
                    425:                        return (NULL);
                    426:                bufsize = ptsize;
                    427:        }
1.18      christos  428:        for (;;) {
1.16      sommerfe  429:                len = __getcwd(pt, bufsize);
                    430:                if ((len < 0) && (size == 0) && (errno == ERANGE)) {
1.20      sommerfe  431:                        if (ptsize > (MAXPATHLEN*4))
                    432:                                return NULL;
1.16      sommerfe  433:                        if ((pt = realloc(pt, ptsize *= 2)) == NULL)
                    434:                                return NULL;
                    435:                        bufsize = ptsize;
                    436:                        continue;
                    437:                }
1.18      christos  438:                break;
                    439:        }
1.16      sommerfe  440:        if (len < 0)
                    441:                return NULL;
                    442:        else
                    443:                return pt;
                    444: }
                    445:
                    446: #endif

CVSweb <webmaster@jp.NetBSD.org>