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1 | .\" Copyright (c) 1983 Regents of the University of California. |
2 | .\" All rights reserved. The Berkeley software License Agreement | |
3 | .\" specifies the terms and conditions for redistribution. | |
4 | .\" | |
01cc7fcc | 5 | .\" @(#)directory.3 6.3 (Berkeley) %G% |
577ec8b7 | 6 | .\" |
600e5e8e | 7 | .TH DIRECTORY 3 "" |
577ec8b7 KM |
8 | .UC 5 |
9 | .SH NAME | |
01cc7fcc | 10 | opendir, readdir, telldir, seekdir, rewinddir, closedir, dirfd \- directory operations |
577ec8b7 | 11 | .SH SYNOPSIS |
600e5e8e | 12 | .B #include <sys/types.h> |
70086ecd | 13 | .br |
577ec8b7 KM |
14 | .B #include <sys/dir.h> |
15 | .PP | |
16 | .SM | |
17 | .B DIR | |
18 | .B *opendir(filename) | |
19 | .br | |
20 | .B char *filename; | |
21 | .PP | |
22 | .B struct direct | |
23 | .B *readdir(dirp) | |
24 | .br | |
25 | .SM | |
26 | .B DIR | |
27 | .B *dirp; | |
28 | .PP | |
29 | .B long | |
30 | .B telldir(dirp) | |
31 | .br | |
32 | .SM | |
33 | .B DIR | |
34 | .B *dirp; | |
35 | .PP | |
36 | .B seekdir(dirp, loc) | |
37 | .br | |
38 | .SM | |
39 | .B DIR | |
40 | .B *dirp; | |
41 | .br | |
42 | .B long loc; | |
43 | .PP | |
44 | .B rewinddir(dirp) | |
45 | .br | |
46 | .SM | |
47 | .B DIR | |
48 | .B *dirp; | |
49 | .PP | |
50 | .B closedir(dirp) | |
51 | .br | |
52 | .SM | |
53 | .B DIR | |
54 | .B *dirp; | |
01cc7fcc KB |
55 | .PP |
56 | .B dirfd(dirp) | |
57 | .br | |
58 | .SM | |
59 | .B DIR | |
60 | .B *dirp; | |
577ec8b7 KM |
61 | .SH DESCRIPTION |
62 | .I Opendir | |
63 | opens the directory named by | |
64 | .I filename | |
65 | and associates a | |
66 | .I directory stream | |
67 | with it. | |
68 | .I Opendir | |
69 | returns a pointer to be used to identify the | |
70 | .I directory stream | |
71 | in subsequent operations. The pointer | |
72 | .SM | |
73 | .B NULL | |
74 | is returned if | |
75 | .I filename | |
76 | cannot be accessed, or if it cannot | |
77 | .IR malloc (3) | |
78 | enough memory to hold the whole thing. | |
79 | .PP | |
80 | .I Readdir | |
81 | returns a pointer to the next directory entry. It returns | |
82 | .B NULL | |
83 | upon reaching the end of the directory or detecting an invalid | |
84 | .I seekdir | |
85 | operation. | |
86 | .PP | |
87 | .I Telldir | |
88 | returns the current location associated with the named | |
89 | .I directory stream. | |
90 | .PP | |
91 | .I Seekdir | |
92 | sets the position of the next | |
93 | .I readdir | |
94 | operation on the | |
95 | .I directory stream. | |
96 | The new position reverts to the one associated with the | |
97 | .I directory stream | |
98 | when the | |
99 | .I telldir | |
100 | operation was performed. Values returned by | |
101 | .I telldir | |
102 | are good only for the lifetime of the DIR pointer from which they are derived. | |
103 | If the directory is closed and then reopened, the | |
104 | .I telldir | |
105 | value may be invalidated due to undetected directory compaction. | |
106 | It is safe to use a previous | |
107 | .I telldir | |
108 | value immediately after a call to | |
109 | .I opendir | |
110 | and before any calls to | |
111 | .I readdir. | |
112 | .PP | |
113 | .I Rewinddir | |
114 | resets the position of the named | |
115 | .I directory stream | |
116 | to the beginning of the directory. | |
117 | .PP | |
118 | .I Closedir | |
119 | closes the named | |
120 | .I directory stream | |
121 | and frees the structure associated with the DIR pointer. | |
122 | .PP | |
01cc7fcc KB |
123 | .I Dirfd |
124 | returns the integer file descriptor associated with the named | |
125 | .I directory stream, | |
126 | see open(2). | |
127 | .PP | |
577ec8b7 KM |
128 | Sample code which searchs a directory for entry ``name'' is: |
129 | .PP | |
130 | .br | |
131 | len = strlen(name); | |
132 | .br | |
133 | dirp = opendir("."); | |
134 | .br | |
135 | for (dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) | |
136 | .br | |
137 | if (dp->d_namlen == len && !strcmp(dp->d_name, name)) { | |
138 | .br | |
139 | closedir(dirp); | |
140 | .br | |
141 | return FOUND; | |
142 | .br | |
143 | } | |
144 | .br | |
145 | closedir(dirp); | |
146 | .br | |
147 | return NOT_FOUND; | |
148 | .SH "SEE ALSO" | |
149 | open(2), | |
150 | close(2), | |
151 | read(2), | |
152 | lseek(2), | |
153 | dir(5) |