xref: /freebsd/lib/libc/gen/getfsent.3 (revision 1da7f3f6f72b2245e458fc7195733268ae4a1136)
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28.Dd April 7, 2003
29.Dt GETFSENT 3
30.Os
31.Sh NAME
32.Nm getfsent ,
33.Nm getfsspec ,
34.Nm getfsfile ,
35.Nm setfsent ,
36.Nm endfsent
37.Nd get file system descriptor file entry
38.Sh LIBRARY
39.Lb libc
40.Sh SYNOPSIS
41.In fstab.h
42.Ft "struct fstab *"
43.Fn getfsent void
44.Ft "struct fstab *"
45.Fn getfsspec "const char *spec"
46.Ft "struct fstab *"
47.Fn getfsfile "const char *file"
48.Ft int
49.Fn setfsent void
50.Ft void
51.Fn endfsent void
52.Ft void
53.Fn setfstab "const char *file"
54.Ft "const char *"
55.Fn getfstab void
56.Sh DESCRIPTION
57The
58.Fn getfsent ,
59.Fn getfsspec ,
60and
61.Fn getfsfile
62functions
63each return a pointer to an object with the following structure
64containing the broken-out fields of a line in the file system
65description file,
66.In fstab.h .
67.Bd -literal -offset indent
68struct fstab {
69	char	*fs_spec;	/* block special device name */
70	char	*fs_file;	/* file system path prefix */
71	char	*fs_vfstype;	/* File system type, ufs, nfs */
72	char	*fs_mntops;	/* Mount options ala -o */
73	char	*fs_type;	/* FSTAB_* from fs_mntops */
74	int	fs_freq;	/* dump frequency, in days */
75	int	fs_passno;	/* pass number on parallel fsck */
76};
77.Ed
78.Pp
79The fields have meanings described in
80.Xr fstab 5 .
81.Pp
82The
83.Fn setfsent
84function
85opens the file (closing any previously opened file) or rewinds it
86if it is already open.
87.Pp
88The
89.Fn endfsent
90function
91closes the file.
92.Pp
93The
94.Fn setfstab
95function sets the file to be used by subsequent operations.
96The value set by
97.Fn setfstab
98does not persist across calls to
99.Fn endfsent .
100.Pp
101The
102.Fn getfstab
103function returns the name of the file that will be used.
104.Pp
105The
106.Fn getfsspec
107and
108.Fn getfsfile
109functions
110search the entire file (opening it if necessary) for a matching special
111file name or file system file name.
112.Pp
113For programs wishing to read the entire database,
114.Fn getfsent
115reads the next entry (opening the file if necessary).
116.Pp
117All entries in the file with a type field equivalent to
118.Dv FSTAB_XX
119are ignored.
120.Sh RETURN VALUES
121The
122.Fn getfsent ,
123.Fn getfsspec ,
124and
125.Fn getfsfile
126functions
127return a
128.Dv NULL
129pointer on
130.Dv EOF
131or error.
132The
133.Fn setfsent
134function
135returns 0 on failure, 1 on success.
136The
137.Fn endfsent
138function
139returns nothing.
140.Sh ENVIRONMENT
141.Bl -tag -width ".Ev PATH_FSTAB"
142.It Ev PATH_FSTAB
143If the environment variable
144.Ev PATH_FSTAB
145is set, all operations are performed against the specified file.
146.Ev PATH_FSTAB
147will not be honored if the process environment or memory address space is
148considered
149.Dq tainted .
150(See
151.Xr issetugid 2
152for more information.)
153.El
154.Sh FILES
155.Bl -tag -width /etc/fstab -compact
156.It Pa /etc/fstab
157.El
158.Sh SEE ALSO
159.Xr fstab 5
160.Sh HISTORY
161The
162.Fn getfsent
163function appeared in
164.Bx 4.0 ;
165the
166.Fn endfsent ,
167.Fn getfsfile ,
168.Fn getfsspec ,
169and
170.Fn setfsent
171functions appeared in
172.Bx 4.3 ;
173the
174.Fn setfstab
175and
176.Fn getfstab
177functions appeared in
178.Fx 5.1 .
179.Sh BUGS
180These functions use static data storage;
181if the data is needed for future use, it should be
182copied before any subsequent calls overwrite it.
183