gsasl  1.10.0
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getcwd-lgpl.c
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1 /* Copyright (C) 2011-2021 Free Software Foundation, Inc.
2  This file is part of gnulib.
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
15  along with this program. If not, see <https://www.gnu.org/licenses/>. */
16 
17 #include <config.h>
18 
19 /* Specification */
20 #include <unistd.h>
21 
22 #include <errno.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #if GNULIB_GETCWD
27 /* Favor GPL getcwd.c if both getcwd and getcwd-lgpl modules are in use. */
28 typedef int dummy;
29 #else
30 
31 /* Get the name of the current working directory, and put it in SIZE
32  bytes of BUF. Returns NULL if the directory couldn't be determined
33  (perhaps because the absolute name was longer than PATH_MAX, or
34  because of missing read/search permissions on parent directories)
35  or SIZE was too small. If successful, returns BUF. If BUF is
36  NULL, an array is allocated with 'malloc'; the array is SIZE bytes
37  long, unless SIZE == 0, in which case it is as big as
38  necessary. */
39 
40 # undef getcwd
41 # if defined _WIN32 && !defined __CYGWIN__
42 # define getcwd _getcwd
43 # endif
44 
45 char *
46 rpl_getcwd (char *buf, size_t size)
47 {
48  char *ptr;
49  char *result;
50 
51  /* Handle single size operations. */
52  if (buf)
53  {
54  if (!size)
55  {
56  errno = EINVAL;
57  return NULL;
58  }
59  return getcwd (buf, size);
60  }
61 
62  if (size)
63  {
64  buf = malloc (size);
65  if (!buf)
66  {
67  errno = ENOMEM;
68  return NULL;
69  }
70  result = getcwd (buf, size);
71  if (!result)
72  {
73  int saved_errno = errno;
74  free (buf);
75  errno = saved_errno;
76  }
77  return result;
78  }
79 
80  /* Flexible sizing requested. Avoid over-allocation for the common
81  case of a name that fits within a 4k page, minus some space for
82  local variables, to be sure we don't skip over a guard page. */
83  {
84  char tmp[4032];
85  size = sizeof tmp;
86  ptr = getcwd (tmp, size);
87  if (ptr)
88  {
89  result = strdup (ptr);
90  if (!result)
91  errno = ENOMEM;
92  return result;
93  }
94  if (errno != ERANGE)
95  return NULL;
96  }
97 
98  /* My what a large directory name we have. */
99  do
100  {
101  size <<= 1;
102  ptr = realloc (buf, size);
103  if (ptr == NULL)
104  {
105  free (buf);
106  errno = ENOMEM;
107  return NULL;
108  }
109  buf = ptr;
110  result = getcwd (buf, size);
111  }
112  while (!result && errno == ERANGE);
113 
114  if (!result)
115  {
116  int saved_errno = errno;
117  free (buf);
118  errno = saved_errno;
119  }
120  else
121  {
122  /* Here result == buf. */
123  /* Shrink result before returning it. */
124  size_t actual_size = strlen (result) + 1;
125  if (actual_size < size)
126  {
127  char *shrinked_result = realloc (result, actual_size);
128  if (shrinked_result != NULL)
129  result = shrinked_result;
130  }
131  }
132  return result;
133 }
134 
135 #endif
int dummy
Definition: float.c:32
#define NULL
Definition: stddef.in.h:72
char * rpl_getcwd(char *buf, size_t size)
Definition: getcwd-lgpl.c:46
static gss_OID_desc tmp
Definition: gss-extra.c:38
char buf[4]
Definition: mbrtowc-impl.h:39
char * strdup(const char *s)
Definition: strdup.c:39