* misc/regexp.h (compile): Use __REPB_PREFIX macro.
[glibc.git] / misc / mntent_r.c
blob829750b395b51b8c9ec0558fc0208f14fe5898d5
1 /* Utilities for reading/writing fstab, mtab, etc.
2 Copyright (C) 1995-2000, 2001, 2002, 2003, 2006
3 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA. */
21 #include <alloca.h>
22 #include <mntent.h>
23 #include <stdio.h>
24 #include <stdio_ext.h>
25 #include <string.h>
26 #include <sys/types.h>
28 #ifdef USE_IN_LIBIO
29 # define flockfile(s) _IO_flockfile (s)
30 # define funlockfile(s) _IO_funlockfile (s)
31 #endif
33 #undef __setmntent
34 #undef __endmntent
35 #undef __getmntent_r
37 /* Prepare to begin reading and/or writing mount table entries from the
38 beginning of FILE. MODE is as for `fopen'. */
39 FILE *
40 __setmntent (const char *file, const char *mode)
42 /* Extend the mode parameter with "c" to disable cancellation in the
43 I/O functions. */
44 size_t modelen = strlen (mode);
45 char newmode[modelen + 2];
46 memcpy (mempcpy (newmode, mode, modelen), "c", 2);
47 FILE *result = fopen (file, newmode);
49 if (result != NULL)
50 /* We do the locking ourselves. */
51 __fsetlocking (result, FSETLOCKING_BYCALLER);
53 return result;
55 INTDEF(__setmntent)
56 weak_alias (__setmntent, setmntent)
59 /* Close a stream opened with `setmntent'. */
60 int
61 __endmntent (FILE *stream)
63 if (stream) /* SunOS 4.x allows for NULL stream */
64 fclose (stream);
65 return 1; /* SunOS 4.x says to always return 1 */
67 INTDEF(__endmntent)
68 weak_alias (__endmntent, endmntent)
71 /* Since the values in a line are separated by spaces, a name cannot
72 contain a space. Therefore some programs encode spaces in names
73 by the strings "\040". We undo the encoding when reading an entry.
74 The decoding happens in place. */
75 static char *
76 decode_name (char *buf)
78 char *rp = buf;
79 char *wp = buf;
82 if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '4' && rp[3] == '0')
84 /* \040 is a SPACE. */
85 *wp++ = ' ';
86 rp += 3;
88 else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '1')
90 /* \011 is a TAB. */
91 *wp++ = '\t';
92 rp += 3;
94 else if (rp[0] == '\\' && rp[1] == '0' && rp[2] == '1' && rp[3] == '2')
96 /* \012 is a NEWLINE. */
97 *wp++ = '\n';
98 rp += 3;
100 else if (rp[0] == '\\' && rp[1] == '\\')
102 /* We have to escape \\ to be able to represent all characters. */
103 *wp++ = '\\';
104 rp += 1;
106 else if (rp[0] == '\\' && rp[1] == '1' && rp[2] == '3' && rp[3] == '4')
108 /* \134 is also \\. */
109 *wp++ = '\\';
110 rp += 3;
112 else
113 *wp++ = *rp;
114 while (*rp++ != '\0');
116 return buf;
120 /* Read one mount table entry from STREAM. Returns a pointer to storage
121 reused on the next call, or null for EOF or error (use feof/ferror to
122 check). */
123 struct mntent *
124 __getmntent_r (FILE *stream, struct mntent *mp, char *buffer, int bufsiz)
126 char *cp;
127 char *head;
129 flockfile (stream);
132 char *end_ptr;
134 if (fgets_unlocked (buffer, bufsiz, stream) == NULL)
136 funlockfile (stream);
137 return NULL;
140 end_ptr = strchr (buffer, '\n');
141 if (end_ptr != NULL) /* chop newline */
142 *end_ptr = '\0';
143 else
145 /* Not the whole line was read. Do it now but forget it. */
146 char tmp[1024];
147 while (fgets_unlocked (tmp, sizeof tmp, stream) != NULL)
148 if (strchr (tmp, '\n') != NULL)
149 break;
152 head = buffer + strspn (buffer, " \t");
153 /* skip empty lines and comment lines: */
155 while (head[0] == '\0' || head[0] == '#');
157 cp = __strsep (&head, " \t");
158 mp->mnt_fsname = cp != NULL ? decode_name (cp) : (char *) "";
159 if (head)
160 head += strspn (head, " \t");
161 cp = __strsep (&head, " \t");
162 mp->mnt_dir = cp != NULL ? decode_name (cp) : (char *) "";
163 if (head)
164 head += strspn (head, " \t");
165 cp = __strsep (&head, " \t");
166 mp->mnt_type = cp != NULL ? decode_name (cp) : (char *) "";
167 if (head)
168 head += strspn (head, " \t");
169 cp = __strsep (&head, " \t");
170 mp->mnt_opts = cp != NULL ? decode_name (cp) : (char *) "";
171 switch (head ? sscanf (head, " %d %d ", &mp->mnt_freq, &mp->mnt_passno) : 0)
173 case 0:
174 mp->mnt_freq = 0;
175 case 1:
176 mp->mnt_passno = 0;
177 case 2:
178 break;
180 funlockfile (stream);
182 return mp;
184 INTDEF(__getmntent_r)
185 weak_alias (__getmntent_r, getmntent_r)
188 /* We have to use an encoding for names if they contain spaces or tabs.
189 To be able to represent all characters we also have to escape the
190 backslash itself. This "function" must be a macro since we use
191 `alloca'. */
192 #define encode_name(name) \
193 do { \
194 const char *rp = name; \
196 while (*rp != '\0') \
197 if (*rp == ' ' || *rp == '\t' || *rp == '\\') \
198 break; \
199 else \
200 ++rp; \
202 if (*rp != '\0') \
204 /* In the worst case the length of the string can increase to \
205 founr times the current length. */ \
206 char *wp; \
208 rp = name; \
209 name = wp = (char *) alloca (strlen (name) * 4 + 1); \
211 do \
212 if (*rp == ' ') \
214 *wp++ = '\\'; \
215 *wp++ = '0'; \
216 *wp++ = '4'; \
217 *wp++ = '0'; \
219 else if (*rp == '\t') \
221 *wp++ = '\\'; \
222 *wp++ = '0'; \
223 *wp++ = '1'; \
224 *wp++ = '1'; \
226 else if (*rp == '\n') \
228 *wp++ = '\\'; \
229 *wp++ = '0'; \
230 *wp++ = '1'; \
231 *wp++ = '2'; \
233 else if (*rp == '\\') \
235 *wp++ = '\\'; \
236 *wp++ = '\\'; \
238 else \
239 *wp++ = *rp; \
240 while (*rp++ != '\0'); \
242 } while (0)
245 /* Write the mount table entry described by MNT to STREAM.
246 Return zero on success, nonzero on failure. */
248 __addmntent (FILE *stream, const struct mntent *mnt)
250 struct mntent mntcopy = *mnt;
251 if (fseek (stream, 0, SEEK_END))
252 return 1;
254 /* Encode spaces and tabs in the names. */
255 encode_name (mntcopy.mnt_fsname);
256 encode_name (mntcopy.mnt_dir);
257 encode_name (mntcopy.mnt_type);
258 encode_name (mntcopy.mnt_opts);
260 return (fprintf (stream, "%s %s %s %s %d %d\n",
261 mntcopy.mnt_fsname,
262 mntcopy.mnt_dir,
263 mntcopy.mnt_type,
264 mntcopy.mnt_opts,
265 mntcopy.mnt_freq,
266 mntcopy.mnt_passno)
267 < 0 ? 1 : 0);
269 weak_alias (__addmntent, addmntent)
272 /* Search MNT->mnt_opts for an option matching OPT.
273 Returns the address of the substring, or null if none found. */
274 char *
275 __hasmntopt (const struct mntent *mnt, const char *opt)
277 const size_t optlen = strlen (opt);
278 char *rest = mnt->mnt_opts, *p;
280 while ((p = strstr (rest, opt)) != NULL)
282 if ((p == rest || p[-1] == ',')
283 && (p[optlen] == '\0' || p[optlen] == '=' || p[optlen] == ','))
284 return p;
286 rest = strchr (p, ',');
287 if (rest == NULL)
288 break;
289 ++rest;
292 return NULL;
294 weak_alias (__hasmntopt, hasmntopt)