source: rtems/c/src/lib/libc/getcwd.c @ 4de102cc

4.104.114.84.95
Last change on this file since 4de102cc was 9c49db4, checked in by Joel Sherrill <joel.sherrill@…>, on 01/08/01 at 18:26:44

2001-01-08 Ralf Corsepius <corsepiu@…>

  • configure.in: Add libc/config.h
  • libc/Makefile.am: Add INCLUDES += -I. to pickup config.h
  • libc/.cvsignore: Add config.h and stamp-h
  • libc/*.c: Add config.h support.
  • Property mode set to 100644
File size: 7.0 KB
Line 
1/*
2 * Copyright (c) 1989, 1991 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *      This product includes software developed by the University of
16 *      California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *  Copied from newlib 1.8.1.  RTEMS can not build all of the contents
34 *  of the UNIX directory but we need this routine.
35 *
36 *  $Id$
37 */
38
39#if HAVE_CONFIG_H
40#include "config.h"
41#endif
42
43/*
44 *  Added these when moved to RTEMS
45 */
46
47#define _stat     stat
48#define _opendir  opendir
49#define _fstat    fstat
50#define _readdir  readdir
51#define _closedir closedir
52
53#if defined(LIBC_SCCS) && !defined(lint)
54static char sccsid[] = "@(#)getcwd.c    5.11 (Berkeley) 2/24/91";
55#endif /* LIBC_SCCS and not lint */
56
57#include <sys/stat.h>
58#include <errno.h>
59#include <dirent.h>
60#include <stdio.h>
61#include <stdlib.h>
62#include <string.h>
63#include <unistd.h>
64#include <reent.h>
65#include <_syslist.h>
66
67#define bcopy(a,b,c)    memmove (b,a,c)
68
69#define ISDOT(dp) \
70        (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
71            (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
72
73#ifndef _REENT_ONLY
74
75char *
76getcwd (pt, size)
77     char *pt;
78     size_t size;
79{
80  register struct dirent *dp;
81  register DIR *dir = 0;
82  register dev_t dev;
83  register ino_t ino;
84  register int first;
85  register char *bpt, *bup;
86  struct stat s;
87  dev_t root_dev;
88  ino_t root_ino;
89  size_t ptsize, upsize;
90  int save_errno;
91  char *ept, *eup, *up;
92
93  /*
94   * If no buffer specified by the user, allocate one as necessary.
95   * If a buffer is specified, the size has to be non-zero.  The path
96   * is built from the end of the buffer backwards.
97   */
98
99  if (pt)
100    {
101      ptsize = 0;
102      if (!size)
103        {
104          errno = EINVAL;
105          return (char *) NULL;
106        }
107      ept = pt + size;
108    }
109  else
110    {
111      if (!(pt = (char *) malloc (ptsize = 1024 - 4)))
112        {
113          return (char *) NULL;
114        }
115      ept = pt + ptsize;
116    }
117  bpt = ept - 1;
118  *bpt = '\0';
119
120  /*
121   * Allocate bytes (1024 - malloc space) for the string of "../"'s.
122   * Should always be enough (it's 340 levels).  If it's not, allocate
123   * as necessary.  Special * case the first stat, it's ".", not "..".
124   */
125
126  if (!(up = (char *) malloc (upsize = 1024 - 4)))
127    {
128      goto err;
129    }
130  eup = up + MAXPATHLEN;
131  bup = up;
132  up[0] = '.';
133  up[1] = '\0';
134
135  /* Save root values, so know when to stop. */
136  if (stat ("/", &s))
137    goto err;
138  root_dev = s.st_dev;
139  root_ino = s.st_ino;
140
141  errno = 0;                    /* XXX readdir has no error return. */
142
143  for (first = 1;; first = 0)
144    {
145      /* Stat the current level. */
146      if (_stat (up, &s))
147        goto err;
148
149      /* Save current node values. */
150      ino = s.st_ino;
151      dev = s.st_dev;
152
153      /* Check for reaching root. */
154      if (root_dev == dev && root_ino == ino)
155        {
156          *--bpt = '/';
157          /*
158           * It's unclear that it's a requirement to copy the
159           * path to the beginning of the buffer, but it's always
160           * been that way and stuff would probably break.
161           */
162          (void) bcopy (bpt, pt, ept - bpt);
163          free (up);
164          return pt;
165        }
166
167      /*
168       * Build pointer to the parent directory, allocating memory
169       * as necessary.  Max length is 3 for "../", the largest
170       * possible component name, plus a trailing NULL.
171       */
172
173      if (bup + 3 + MAXNAMLEN + 1 >= eup)
174        {
175          if (!(up = (char *) realloc (up, upsize *= 2)))
176            {
177              goto err;
178            }
179          bup = up;
180          eup = up + upsize;
181        }
182      *bup++ = '.';
183      *bup++ = '.';
184      *bup = '\0';
185
186      /* Open and stat parent directory. */
187      if (!(dir = _opendir (up)) || _fstat (__dirfd (dir), &s))
188        goto err;
189
190      /* Add trailing slash for next directory. */
191      *bup++ = '/';
192
193      /*
194       * If it's a mount point, have to stat each element because
195       * the inode number in the directory is for the entry in the
196       * parent directory, not the inode number of the mounted file.
197       */
198
199      save_errno = 0;
200      if (s.st_dev == dev)
201        {
202          for (;;)
203            {
204              if (!(dp = _readdir (dir)))
205                goto notfound;
206              if (dp->d_ino == ino)
207                break;
208            }
209        }
210      else
211        for (;;)
212          {
213            if (!(dp = _readdir (dir)))
214              goto notfound;
215            if (ISDOT (dp))
216              continue;
217            bcopy (dp->d_name, bup, strlen (dp->d_name) + 1);
218
219            /* Save the first error for later. */
220            if (stat (up, &s))
221              {
222                if (!save_errno)
223                  save_errno = errno;
224                errno = 0;
225                continue;
226              }
227            if (s.st_dev == dev && s.st_ino == ino)
228              break;
229          }
230
231      /*
232       * Check for length of the current name, preceding slash,
233       * leading slash.
234       */
235
236      if (bpt - pt <= strlen (dp->d_name) + (first ? 1 : 2))
237        {
238          size_t len, off;
239
240          if (!ptsize)
241            {
242              errno = ERANGE;
243              goto err;
244            }
245          off = bpt - pt;
246          len = ept - bpt;
247          if (!(pt = (char *) realloc (pt, ptsize *= 2)))
248            {
249              goto err;
250            }
251          bpt = pt + off;
252          ept = pt + ptsize;
253          (void) bcopy (bpt, ept - len, len);
254          bpt = ept - len;
255        }
256      if (!first)
257        *--bpt = '/';
258      bpt -= strlen (dp->d_name);
259      bcopy (dp->d_name, bpt, strlen (dp->d_name));
260      (void) _closedir (dir);
261      dir = 0;
262
263      /* Truncate any file name. */
264      *bup = '\0';
265    }
266
267notfound:
268  /*
269   * If readdir set errno, use it, not any saved error; otherwise,
270   * didn't find the current directory in its parent directory, set
271   * errno to ENOENT.
272   */
273
274  if (!errno)
275    errno = save_errno ? save_errno : ENOENT;
276  /* FALLTHROUGH */
277
278err:
279  if(dir)
280    (void) _closedir (dir);
281  if (ptsize)
282    free (pt);
283  free (up);
284  return (char *) NULL;
285}
286
287#endif /* _REENT_ONLY */
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