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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [lib/] [libc/] [getcwd.c] - Blame information for rev 507

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1 30 unneback
/*
2
 * Copyright (c) 1989, 1991 The Regents of the University of California.
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
11
 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. All advertising materials mentioning features or use of this software
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 *    must display the following acknowledgement:
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 *      This product includes software developed by the University of
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 *      California, Berkeley and its contributors.
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 * 4. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 *
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 *  Copied from newlib 1.8.1.  RTEMS can not build all of the contents
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 *  of the UNIX directory but we need this routine.
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 *
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 *  $Id: getcwd.c,v 1.2 2001-09-27 12:01:15 chris Exp $
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 */
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/*
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 *  Added these when moved to RTEMS
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 */
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#define _stat     stat
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#define _opendir  opendir
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#define _fstat    fstat
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#define _readdir  readdir
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#define _closedir closedir
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)getcwd.c    5.11 (Berkeley) 2/24/91";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/stat.h>
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#include <errno.h>
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#include <dirent.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <reent.h>
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#include <_syslist.h>
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#define bcopy(a,b,c)    memmove (b,a,c)
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#define ISDOT(dp) \
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        (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
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            (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
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#ifndef _REENT_ONLY
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char *
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getcwd (pt, size)
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     char *pt;
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     size_t size;
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{
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  register struct dirent *dp;
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  register DIR *dir;
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  register dev_t dev;
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  register ino_t ino;
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  register int first;
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  register char *bpt, *bup;
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  struct stat s;
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  dev_t root_dev;
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  ino_t root_ino;
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  size_t ptsize, upsize;
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  int save_errno;
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  char *ept, *eup, *up;
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89
  /*
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   * If no buffer specified by the user, allocate one as necessary.
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   * If a buffer is specified, the size has to be non-zero.  The path
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   * is built from the end of the buffer backwards.
93
   */
94
 
95
  if (pt)
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    {
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      ptsize = 0;
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      if (!size)
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        {
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          errno = EINVAL;
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          return (char *) NULL;
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        }
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      ept = pt + size;
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    }
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  else
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    {
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      if (!(pt = (char *) malloc (ptsize = 1024 - 4)))
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        {
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          return (char *) NULL;
110
        }
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      ept = pt + ptsize;
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    }
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  bpt = ept - 1;
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  *bpt = '\0';
115
 
116
  /*
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   * Allocate bytes (1024 - malloc space) for the string of "../"'s.
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   * Should always be enough (it's 340 levels).  If it's not, allocate
119
   * as necessary.  Special * case the first stat, it's ".", not "..".
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   */
121
 
122
  if (!(up = (char *) malloc (upsize = 1024 - 4)))
123
    {
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      goto err;
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    }
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  eup = up + MAXPATHLEN;
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  bup = up;
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  up[0] = '.';
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  up[1] = '\0';
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131
  /* Save root values, so know when to stop. */
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  if (stat ("/", &s))
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    goto err;
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  root_dev = s.st_dev;
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  root_ino = s.st_ino;
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137
  errno = 0;                     /* XXX readdir has no error return. */
138
 
139
  for (first = 1;; first = 0)
140
    {
141
      /* Stat the current level. */
142
      if (_stat (up, &s))
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        goto err;
144
 
145
      /* Save current node values. */
146
      ino = s.st_ino;
147
      dev = s.st_dev;
148
 
149
      /* Check for reaching root. */
150
      if (root_dev == dev && root_ino == ino)
151
        {
152
          *--bpt = '/';
153
          /*
154
           * It's unclear that it's a requirement to copy the
155
           * path to the beginning of the buffer, but it's always
156
           * been that way and stuff would probably break.
157
           */
158
          (void) bcopy (bpt, pt, ept - bpt);
159
          free (up);
160
          return pt;
161
        }
162
 
163
      /*
164
       * Build pointer to the parent directory, allocating memory
165
       * as necessary.  Max length is 3 for "../", the largest
166
       * possible component name, plus a trailing NULL.
167
       */
168
 
169
      if (bup + 3 + MAXNAMLEN + 1 >= eup)
170
        {
171
          if (!(up = (char *) realloc (up, upsize *= 2)))
172
            {
173
              goto err;
174
            }
175
          bup = up;
176
          eup = up + upsize;
177
        }
178
      *bup++ = '.';
179
      *bup++ = '.';
180
      *bup = '\0';
181
 
182
      /* Open and stat parent directory. */
183
      if (!(dir = _opendir (up)) || _fstat (__dirfd (dir), &s))
184
        goto err;
185
 
186
      /* Add trailing slash for next directory. */
187
      *bup++ = '/';
188
 
189
      /*
190
       * If it's a mount point, have to stat each element because
191
       * the inode number in the directory is for the entry in the
192
       * parent directory, not the inode number of the mounted file.
193
       */
194
 
195
      save_errno = 0;
196
      if (s.st_dev == dev)
197
        {
198
          for (;;)
199
            {
200
              if (!(dp = _readdir (dir)))
201
                goto notfound;
202
              if (dp->d_ino == ino)
203
                break;
204
            }
205
        }
206
      else
207
        for (;;)
208
          {
209
            if (!(dp = _readdir (dir)))
210
              goto notfound;
211
            if (ISDOT (dp))
212
              continue;
213
            bcopy (dp->d_name, bup, strlen (dp->d_name) + 1);
214
 
215
            /* Save the first error for later. */
216
            if (stat (up, &s))
217
              {
218
                if (!save_errno)
219
                  save_errno = errno;
220
                errno = 0;
221
                continue;
222
              }
223
            if (s.st_dev == dev && s.st_ino == ino)
224
              break;
225
          }
226
 
227
      /*
228
       * Check for length of the current name, preceding slash,
229
       * leading slash.
230
       */
231
 
232
      if (bpt - pt <= strlen (dp->d_name) + (first ? 1 : 2))
233
        {
234
          size_t len, off;
235
 
236
          if (!ptsize)
237
            {
238
              errno = ERANGE;
239
              goto err;
240
            }
241
          off = bpt - pt;
242
          len = ept - bpt;
243
          if (!(pt = (char *) realloc (pt, ptsize *= 2)))
244
            {
245
              goto err;
246
            }
247
          bpt = pt + off;
248
          ept = pt + ptsize;
249
          (void) bcopy (bpt, ept - len, len);
250
          bpt = ept - len;
251
        }
252
      if (!first)
253
        *--bpt = '/';
254
      bpt -= strlen (dp->d_name);
255
      bcopy (dp->d_name, bpt, strlen (dp->d_name));
256
      (void) _closedir (dir);
257
 
258
      /* Truncate any file name. */
259
      *bup = '\0';
260
    }
261
 
262
notfound:
263
  /*
264
   * If readdir set errno, use it, not any saved error; otherwise,
265
   * didn't find the current directory in its parent directory, set
266
   * errno to ENOENT.
267
   */
268
 
269
  if (!errno)
270
    errno = save_errno ? save_errno : ENOENT;
271
  /* FALLTHROUGH */
272
 
273
err:
274
  if (ptsize)
275
    free (pt);
276
  free (up);
277
  return (char *) NULL;
278
}
279
 
280
#endif /* _REENT_ONLY */

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