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Annotation of embedaddon/libiconv/srclib/readlink.c, revision 1.1.1.3

1.1       misho       1: /* Stub for readlink().
1.1.1.3 ! misho       2:    Copyright (C) 2003-2007, 2009-2019 Free Software Foundation, Inc.
1.1       misho       3: 
                      4:    This program is free software: you can redistribute it and/or modify
                      5:    it under the terms of the GNU General Public License as published by
                      6:    the Free Software Foundation; either version 3 of the License, or
                      7:    (at your option) any later version.
                      8: 
                      9:    This program is distributed in the hope that it will be useful,
                     10:    but WITHOUT ANY WARRANTY; without even the implied warranty of
                     11:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     12:    GNU General Public License for more details.
                     13: 
                     14:    You should have received a copy of the GNU General Public License
1.1.1.3 ! misho      15:    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
1.1       misho      16: 
                     17: #include <config.h>
                     18: 
                     19: /* Specification.  */
                     20: #include <unistd.h>
                     21: 
                     22: #include <errno.h>
1.1.1.2   misho      23: #include <string.h>
1.1       misho      24: #include <sys/stat.h>
                     25: 
                     26: #if !HAVE_READLINK
                     27: 
                     28: /* readlink() substitute for systems that don't have a readlink() function,
                     29:    such as DJGPP 2.03 and mingw32.  */
                     30: 
1.1.1.2   misho      31: ssize_t
                     32: readlink (const char *name, char *buf _GL_UNUSED,
                     33:           size_t bufsize _GL_UNUSED)
1.1       misho      34: {
                     35:   struct stat statbuf;
                     36: 
                     37:   /* In general we should use lstat() here, not stat().  But on platforms
1.1.1.2   misho      38:      without symbolic links, lstat() - if it exists - would be equivalent to
1.1       misho      39:      stat(), therefore we can use stat().  This saves us a configure check.  */
1.1.1.2   misho      40:   if (stat (name, &statbuf) >= 0)
1.1       misho      41:     errno = EINVAL;
                     42:   return -1;
                     43: }
                     44: 
1.1.1.2   misho      45: #else /* HAVE_READLINK */
                     46: 
                     47: # undef readlink
                     48: 
                     49: /* readlink() wrapper that uses correct types, for systems like cygwin
                     50:    1.5.x where readlink returns int, and which rejects trailing slash,
                     51:    for Solaris 9.  */
                     52: 
                     53: ssize_t
                     54: rpl_readlink (const char *name, char *buf, size_t bufsize)
                     55: {
                     56: # if READLINK_TRAILING_SLASH_BUG
                     57:   size_t len = strlen (name);
                     58:   if (len && name[len - 1] == '/')
                     59:     {
                     60:       /* Even if name without the slash is a symlink to a directory,
                     61:          both lstat() and stat() must resolve the trailing slash to
                     62:          the directory rather than the symlink.  We can therefore
                     63:          safely use stat() to distinguish between EINVAL and
                     64:          ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat().  */
                     65:       struct stat st;
                     66:       if (stat (name, &st) == 0)
                     67:         errno = EINVAL;
                     68:       return -1;
                     69:     }
                     70: # endif /* READLINK_TRAILING_SLASH_BUG */
                     71:   return readlink (name, buf, bufsize);
                     72: }
                     73: 
                     74: #endif /* HAVE_READLINK */