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pgmkdirp.c
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1 /*
2  * This is adapted from FreeBSD's src/bin/mkdir/mkdir.c, which bears
3  * the following copyright notice:
4  *
5  * Copyright (c) 1983, 1992, 1993
6  * The Regents of the University of California. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  * notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  * notice, this list of conditions and the following disclaimer in the
15  * documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  * may be used to endorse or promote products derived from this software
18  * without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "c.h"
34 
35 #include <sys/stat.h>
36 
37 
38 /*
39  * pg_mkdir_p --- create a directory and, if necessary, parent directories
40  *
41  * This is equivalent to "mkdir -p" except we don't complain if the target
42  * directory already exists.
43  *
44  * We assume the path is in canonical form, i.e., uses / as the separator.
45  *
46  * omode is the file permissions bits for the target directory. Note that any
47  * parent directories that have to be created get permissions according to the
48  * prevailing umask, but with u+wx forced on to ensure we can create there.
49  * (We declare omode as int, not mode_t, to minimize dependencies for port.h.)
50  *
51  * Returns 0 on success, -1 (with errno set) on failure.
52  *
53  * Note that on failure, the path arg has been modified to show the particular
54  * directory level we had problems with.
55  */
56 int
57 pg_mkdir_p(char *path, int omode)
58 {
59  struct stat sb;
60  mode_t numask,
61  oumask;
62  int last,
63  retval;
64  char *p;
65 
66  retval = 0;
67  p = path;
68 
69 #ifdef WIN32
70  /* skip network and drive specifiers for win32 */
71  if (strlen(p) >= 2)
72  {
73  if (p[0] == '/' && p[1] == '/')
74  {
75  /* network drive */
76  p = strstr(p + 2, "/");
77  if (p == NULL)
78  {
79  errno = EINVAL;
80  return -1;
81  }
82  }
83  else if (p[1] == ':' &&
84  ((p[0] >= 'a' && p[0] <= 'z') ||
85  (p[0] >= 'A' && p[0] <= 'Z')))
86  {
87  /* local drive */
88  p += 2;
89  }
90  }
91 #endif
92 
93  /*
94  * POSIX 1003.2: For each dir operand that does not name an existing
95  * directory, effects equivalent to those caused by the following command
96  * shall occur:
97  *
98  * mkdir -p -m $(umask -S),u+wx $(dirname dir) && mkdir [-m mode] dir
99  *
100  * We change the user's umask and then restore it, instead of doing
101  * chmod's. Note we assume umask() can't change errno.
102  */
103  oumask = umask(0);
104  numask = oumask & ~(S_IWUSR | S_IXUSR);
105  (void) umask(numask);
106 
107  if (p[0] == '/') /* Skip leading '/'. */
108  ++p;
109  for (last = 0; !last; ++p)
110  {
111  if (p[0] == '\0')
112  last = 1;
113  else if (p[0] != '/')
114  continue;
115  *p = '\0';
116  if (!last && p[1] == '\0')
117  last = 1;
118 
119  if (last)
120  (void) umask(oumask);
121 
122  /* check for pre-existing directory */
123  if (stat(path, &sb) == 0)
124  {
125  if (!S_ISDIR(sb.st_mode))
126  {
127  if (last)
128  errno = EEXIST;
129  else
130  errno = ENOTDIR;
131  retval = -1;
132  break;
133  }
134  }
135  else if (mkdir(path, last ? omode : S_IRWXU | S_IRWXG | S_IRWXO) < 0)
136  {
137  retval = -1;
138  break;
139  }
140  if (!last)
141  *p = '/';
142  }
143 
144  /* ensure we restored umask */
145  (void) umask(oumask);
146 
147  return retval;
148 }
#define mkdir(a, b)
Definition: win32.h:57
int pg_mkdir_p(char *path, int omode)
Definition: pgmkdirp.c:57
#define S_IRWXO
Definition: win32.h:455
#define S_IRWXG
Definition: win32.h:451