1 /* Utilities for reading/writing fstab, mtab, etc.
2 Copyright (C) 1995-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
22 #include <stdio_ext.h>
24 #include <sys/types.h>
26 #define flockfile(s) _IO_flockfile (s)
27 #define funlockfile(s) _IO_funlockfile (s)
33 /* Prepare to begin reading and/or writing mount table entries from the
34 beginning of FILE. MODE is as for `fopen'. */
36 __setmntent (const char *file
, const char *mode
)
38 /* Extend the mode parameter with "c" to disable cancellation in the
39 I/O functions and "e" to set FD_CLOEXEC. */
40 size_t modelen
= strlen (mode
);
41 char newmode
[modelen
+ 3];
42 memcpy (mempcpy (newmode
, mode
, modelen
), "ce", 3);
43 FILE *result
= fopen (file
, newmode
);
46 /* We do the locking ourselves. */
47 __fsetlocking (result
, FSETLOCKING_BYCALLER
);
51 libc_hidden_def (__setmntent
)
52 weak_alias (__setmntent
, setmntent
)
55 /* Close a stream opened with `setmntent'. */
57 __endmntent (FILE *stream
)
59 if (stream
) /* SunOS 4.x allows for NULL stream */
61 return 1; /* SunOS 4.x says to always return 1 */
63 libc_hidden_def (__endmntent
)
64 weak_alias (__endmntent
, endmntent
)
67 /* Since the values in a line are separated by spaces, a name cannot
68 contain a space. Therefore some programs encode spaces in names
69 by the strings "\040". We undo the encoding when reading an entry.
70 The decoding happens in place. */
72 decode_name (char *buf
)
78 if (rp
[0] == '\\' && rp
[1] == '0' && rp
[2] == '4' && rp
[3] == '0')
80 /* \040 is a SPACE. */
84 else if (rp
[0] == '\\' && rp
[1] == '0' && rp
[2] == '1' && rp
[3] == '1')
90 else if (rp
[0] == '\\' && rp
[1] == '0' && rp
[2] == '1' && rp
[3] == '2')
92 /* \012 is a NEWLINE. */
96 else if (rp
[0] == '\\' && rp
[1] == '\\')
98 /* We have to escape \\ to be able to represent all characters. */
102 else if (rp
[0] == '\\' && rp
[1] == '1' && rp
[2] == '3' && rp
[3] == '4')
104 /* \134 is also \\. */
110 while (*rp
++ != '\0');
116 /* Read one mount table entry from STREAM. Returns a pointer to storage
117 reused on the next call, or null for EOF or error (use feof/ferror to
120 __getmntent_r (FILE *stream
, struct mntent
*mp
, char *buffer
, int bufsiz
)
130 if (__fgets_unlocked (buffer
, bufsiz
, stream
) == NULL
)
132 funlockfile (stream
);
136 end_ptr
= strchr (buffer
, '\n');
137 if (end_ptr
!= NULL
) /* chop newline */
141 /* Not the whole line was read. Do it now but forget it. */
143 while (__fgets_unlocked (tmp
, sizeof tmp
, stream
) != NULL
)
144 if (strchr (tmp
, '\n') != NULL
)
148 head
= buffer
+ strspn (buffer
, " \t");
149 /* skip empty lines and comment lines: */
151 while (head
[0] == '\0' || head
[0] == '#');
153 cp
= __strsep (&head
, " \t");
154 mp
->mnt_fsname
= cp
!= NULL
? decode_name (cp
) : (char *) "";
156 head
+= strspn (head
, " \t");
157 cp
= __strsep (&head
, " \t");
158 mp
->mnt_dir
= cp
!= NULL
? decode_name (cp
) : (char *) "";
160 head
+= strspn (head
, " \t");
161 cp
= __strsep (&head
, " \t");
162 mp
->mnt_type
= cp
!= NULL
? decode_name (cp
) : (char *) "";
164 head
+= strspn (head
, " \t");
165 cp
= __strsep (&head
, " \t");
166 mp
->mnt_opts
= cp
!= NULL
? decode_name (cp
) : (char *) "";
167 switch (head
? sscanf (head
, " %d %d ", &mp
->mnt_freq
, &mp
->mnt_passno
) : 0)
176 funlockfile (stream
);
180 libc_hidden_def (__getmntent_r
)
181 weak_alias (__getmntent_r
, getmntent_r
)
184 /* We have to use an encoding for names if they contain spaces or tabs.
185 To be able to represent all characters we also have to escape the
186 backslash itself. This "function" must be a macro since we use
188 #define encode_name(name) \
190 const char *rp = name; \
192 while (*rp != '\0') \
193 if (*rp == ' ' || *rp == '\t' || *rp == '\n' || *rp == '\\') \
200 /* In the worst case the length of the string can increase to \
201 four times the current length. */ \
205 name = wp = (char *) alloca (strlen (name) * 4 + 1); \
215 else if (*rp == '\t') \
222 else if (*rp == '\n') \
229 else if (*rp == '\\') \
236 while (*rp++ != '\0'); \
241 /* Write the mount table entry described by MNT to STREAM.
242 Return zero on success, nonzero on failure. */
244 __addmntent (FILE *stream
, const struct mntent
*mnt
)
246 struct mntent mntcopy
= *mnt
;
247 if (fseek (stream
, 0, SEEK_END
))
250 /* Encode spaces and tabs in the names. */
251 encode_name (mntcopy
.mnt_fsname
);
252 encode_name (mntcopy
.mnt_dir
);
253 encode_name (mntcopy
.mnt_type
);
254 encode_name (mntcopy
.mnt_opts
);
256 return (fprintf (stream
, "%s %s %s %s %d %d\n",
262 mntcopy
.mnt_passno
) < 0
263 || fflush (stream
) != 0);
265 weak_alias (__addmntent
, addmntent
)
268 /* Search MNT->mnt_opts for an option matching OPT.
269 Returns the address of the substring, or null if none found. */
271 __hasmntopt (const struct mntent
*mnt
, const char *opt
)
273 const size_t optlen
= strlen (opt
);
274 char *rest
= mnt
->mnt_opts
, *p
;
276 while ((p
= strstr (rest
, opt
)) != NULL
)
278 if ((p
== rest
|| p
[-1] == ',')
279 && (p
[optlen
] == '\0' || p
[optlen
] == '=' || p
[optlen
] == ','))
282 rest
= strchr (p
, ',');
290 weak_alias (__hasmntopt
, hasmntopt
)