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1 | .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
2 | .\" | |
93015253 | 3 | .\" %%%LICENSE_START(VERBATIM) |
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4 | .\" Permission is granted to make and distribute verbatim copies of this |
5 | .\" manual provided the copyright notice and this permission notice are | |
6 | .\" preserved on all copies. | |
7 | .\" | |
8 | .\" Permission is granted to copy and distribute modified versions of this | |
9 | .\" manual under the conditions for verbatim copying, provided that the | |
10 | .\" entire resulting derived work is distributed under the terms of a | |
11 | .\" permission notice identical to this one. | |
c13182ef | 12 | .\" |
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13 | .\" Since the Linux kernel and libraries are constantly changing, this |
14 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
15 | .\" responsibility for errors or omissions, or for damages resulting from | |
16 | .\" the use of the information contained herein. The author(s) may not | |
17 | .\" have taken the same level of care in the production of this manual, | |
18 | .\" which is licensed free of charge, as they might when working | |
19 | .\" professionally. | |
c13182ef | 20 | .\" |
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21 | .\" Formatted or processed versions of this manual, if unaccompanied by |
22 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 23 | .\" %%%LICENSE_END |
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24 | .\" |
25 | .\" References consulted: | |
26 | .\" Linux libc source code | |
27 | .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) | |
28 | .\" 386BSD man pages | |
29 | .\" Modified Sat Jul 24 21:46:57 1993 by Rik Faith (faith@cs.unc.edu) | |
30 | .\" Modified 961109, 031115, aeb | |
31 | .\" | |
4b8c67d9 | 32 | .TH GETMNTENT 3 2017-09-15 "" "Linux Programmer's Manual" |
fea681da MK |
33 | .SH NAME |
34 | getmntent, setmntent, addmntent, endmntent, hasmntopt, | |
9ee4a2b6 | 35 | getmntent_r \- get filesystem descriptor file entry |
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36 | .SH SYNOPSIS |
37 | .nf | |
38 | .B #include <stdio.h> | |
39 | .B #include <mntent.h> | |
68e4db0a | 40 | .PP |
fea681da | 41 | .BI "FILE *setmntent(const char *" filename ", const char *" type ); |
68e4db0a | 42 | .PP |
7de6ef86 | 43 | .BI "struct mntent *getmntent(FILE *" stream ); |
68e4db0a | 44 | .PP |
7de6ef86 | 45 | .BI "int addmntent(FILE *" stream ", const struct mntent *" mnt ); |
68e4db0a | 46 | .PP |
7de6ef86 | 47 | .BI "int endmntent(FILE *" streamp ); |
68e4db0a | 48 | .PP |
fea681da | 49 | .BI "char *hasmntopt(const struct mntent *" mnt ", const char *" opt ); |
f90f031e | 50 | |
fea681da | 51 | /* GNU extension */ |
fea681da | 52 | .B #include <mntent.h> |
68e4db0a | 53 | .PP |
7de6ef86 | 54 | .BI "struct mntent *getmntent_r(FILE *" streamp ", struct mntent *" mntbuf , |
fea681da MK |
55 | .BI " char *" buf ", int " buflen ); |
56 | .fi | |
68e4db0a | 57 | .PP |
cc4615cc MK |
58 | .in -4n |
59 | Feature Test Macro Requirements for glibc (see | |
60 | .BR feature_test_macros (7)): | |
61 | .in | |
68e4db0a | 62 | .PP |
cd74b428 | 63 | .BR getmntent_r (): |
51c612fb MK |
64 | Since glibc 2.19: |
65 | _DEFAULT_SOURCE | |
66 | Glibc 2.19 and earlier: | |
67 | _BSD_SOURCE || _SVID_SOURCE | |
fea681da | 68 | .SH DESCRIPTION |
9ee4a2b6 | 69 | These routines are used to access the filesystem description file |
c6fa0841 | 70 | .I /etc/fstab |
9ee4a2b6 | 71 | and the mounted filesystem description file |
e6c6110c | 72 | .IR /etc/mtab . |
fea681da | 73 | .PP |
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74 | The |
75 | .BR setmntent () | |
9ee4a2b6 | 76 | function opens the filesystem description file |
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77 | .I filename |
78 | and returns a file pointer which can be used by | |
60a90ecd | 79 | .BR getmntent (). |
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80 | The argument |
81 | .I type | |
82 | is the type of access | |
83 | required and can take the same values as the | |
84 | .I mode | |
85 | argument of | |
fea681da | 86 | .BR fopen (3). |
7c2c86ef EH |
87 | The returned stream should be closed using |
88 | .BR endmntent () | |
89 | rather than | |
90 | .BR fclose (3). | |
fea681da | 91 | .PP |
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92 | The |
93 | .BR getmntent () | |
7de6ef86 CD |
94 | function reads the next line of the filesystem |
95 | description file from | |
96 | .I stream | |
c6fa0841 | 97 | and returns a pointer to a structure |
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98 | containing the broken out fields from a line in the file. |
99 | The pointer | |
fea681da | 100 | points to a static area of memory which is overwritten by subsequent |
60a90ecd MK |
101 | calls to |
102 | .BR getmntent (). | |
fea681da | 103 | .PP |
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104 | The |
105 | .BR addmntent () | |
c3022783 MK |
106 | function adds the |
107 | .I mntent | |
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108 | structure |
109 | .I mnt | |
110 | to | |
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111 | the end of the open |
112 | .IR stream . | |
fea681da | 113 | .PP |
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114 | The |
115 | .BR endmntent () | |
7de6ef86 CD |
116 | function closes the |
117 | .IR stream | |
118 | associated with the filesystem description file. | |
fea681da | 119 | .PP |
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120 | The |
121 | .BR hasmntopt () | |
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122 | function scans the |
123 | .I mnt_opts | |
124 | field (see below) | |
c3022783 MK |
125 | of the |
126 | .I mntent | |
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127 | structure |
128 | .I mnt | |
129 | for a substring that matches | |
130 | .IR opt . | |
131 | See | |
132 | .I <mntent.h> | |
133 | and | |
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134 | .BR mount (8) |
135 | for valid mount options. | |
136 | .PP | |
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137 | The reentrant |
138 | .BR getmntent_r () | |
139 | function is similar to | |
140 | .BR getmntent (), | |
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141 | but stores the |
142 | .IR "struct mount" | |
143 | in the provided | |
bd9b2a9c | 144 | .I *mntbuf |
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145 | and stores the strings pointed to by the entries in that struct |
146 | in the provided array | |
147 | .I buf | |
148 | of size | |
149 | .IR buflen . | |
150 | .PP | |
c6fa0841 MK |
151 | The |
152 | .I mntent | |
153 | structure is defined in | |
154 | .I <mntent.h> | |
155 | as follows: | |
51f5698d | 156 | .PP |
a08ea57c | 157 | .in +4n |
b8302363 | 158 | .EX |
fea681da | 159 | struct mntent { |
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160 | char *mnt_fsname; /* name of mounted filesystem */ |
161 | char *mnt_dir; /* filesystem path prefix */ | |
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162 | char *mnt_type; /* mount type (see mntent.h) */ |
163 | char *mnt_opts; /* mount options (see mntent.h) */ | |
164 | int mnt_freq; /* dump frequency in days */ | |
165 | int mnt_passno; /* pass number on parallel fsck */ | |
fea681da | 166 | }; |
b8302363 | 167 | .EE |
a08ea57c | 168 | .in |
847e0d88 | 169 | .PP |
fea681da | 170 | Since fields in the mtab and fstab files are separated by whitespace, |
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171 | octal escapes are used to represent the characters space (\e040), |
172 | tab (\e011), newline (\e012), and backslash (\e\e) in those files | |
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173 | when they occur in one of the four strings in a |
174 | .I mntent | |
175 | structure. | |
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176 | The routines |
177 | .BR addmntent () | |
178 | and | |
179 | .BR getmntent () | |
180 | will convert | |
fea681da | 181 | from string representation to escaped representation and back. |
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182 | When converting from escaped representation, the sequence \e134 is |
183 | also converted to a backslash. | |
47297adb | 184 | .SH RETURN VALUE |
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185 | The |
186 | .BR getmntent () | |
187 | and | |
188 | .BR getmntent_r () | |
189 | functions return | |
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190 | a pointer to the |
191 | .I mntent | |
192 | structure or NULL on failure. | |
fea681da | 193 | .PP |
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194 | The |
195 | .BR addmntent () | |
196 | function returns 0 on success and 1 on failure. | |
fea681da | 197 | .PP |
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198 | The |
199 | .BR endmntent () | |
200 | function always returns 1. | |
fea681da | 201 | .PP |
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202 | The |
203 | .BR hasmntopt () | |
204 | function returns the address of the substring if | |
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205 | a match is found and NULL otherwise. |
206 | .SH FILES | |
d0b8a8d8 MK |
207 | .TP |
208 | .I /etc/fstab | |
209 | filesystem description file | |
210 | .TP | |
211 | .I /etc/mtab | |
212 | mounted filesystem description file | |
b7a0a144 ZL |
213 | .SH ATTRIBUTES |
214 | For an explanation of the terms used in this section, see | |
215 | .BR attributes (7). | |
74714ea8 | 216 | .ad l |
b7a0a144 ZL |
217 | .TS |
218 | allbox; | |
219 | lbw13 lb lbw31 | |
220 | l l l. | |
221 | Interface Attribute Value | |
222 | T{ | |
223 | .BR setmntent (), | |
224 | .BR endmntent (), | |
225 | .BR hasmntopt () | |
226 | T} Thread safety MT-Safe | |
227 | T{ | |
228 | .BR getmntent () | |
229 | T} Thread safety MT-Unsafe race:mntentbuf locale | |
230 | T{ | |
231 | .BR addmntent () | |
232 | T} Thread safety MT-Safe race:stream locale | |
233 | T{ | |
234 | .BR getmntent_r () | |
235 | T} Thread safety MT-Safe locale | |
236 | .TE | |
74714ea8 | 237 | .ad |
47297adb | 238 | .SH CONFORMING TO |
54d75d6c | 239 | The nonreentrant functions are from SunOS 4.1.3. |
fea681da | 240 | A routine |
63aa9df0 | 241 | .BR getmntent_r () |
c13182ef | 242 | was introduced in HP-UX 10, but it returns an int. |
68e1685c | 243 | The prototype shown above is glibc-only. |
fea681da | 244 | .SH NOTES |
60a90ecd MK |
245 | System V also has a |
246 | .BR getmntent () | |
247 | function but the calling sequence | |
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248 | differs, and the returned structure is different. |
249 | Under System V | |
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250 | .I /etc/mnttab |
251 | is used. | |
008f1ecc | 252 | 4.4BSD and Digital UNIX have a routine |
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253 | .BR getmntinfo (), |
254 | a wrapper around the system call | |
255 | .BR getfsstat (). | |
47297adb | 256 | .SH SEE ALSO |
fea681da MK |
257 | .BR fopen (3), |
258 | .BR fstab (5), | |
259 | .BR mount (8) |