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1 | .\" Copyright (c) 1983, 1991, 1993 | |
2 | .\" The Regents of the University of California. All rights reserved. | |
3 | .\" | |
4 | .\" Redistribution and use in source and binary forms, with or without | |
5 | .\" modification, are permitted provided that the following conditions | |
6 | .\" are met: | |
7 | .\" 1. Redistributions of source code must retain the above copyright | |
8 | .\" notice, this list of conditions and the following disclaimer. | |
9 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
10 | .\" notice, this list of conditions and the following disclaimer in the | |
11 | .\" documentation and/or other materials provided with the distribution. | |
12 | .\" 4. Neither the name of the University nor the names of its contributors | |
13 | .\" may be used to endorse or promote products derived from this software | |
14 | .\" without specific prior written permission. | |
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16 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
17 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
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27 | .\" | |
28 | .\" @(#)scandir.3 8.1 (Berkeley) 6/4/93 | |
29 | .\" $FreeBSD: src/lib/libc/gen/scandir.3,v 1.9 2007/01/09 00:27:55 imp Exp $ | |
30 | .\" | |
31 | .Dd May 20, 2008 | |
32 | .Dt SCANDIR 3 | |
33 | .Os | |
34 | .Sh NAME | |
35 | .Nm scandir , | |
36 | #ifdef UNIFDEF_BLOCKS | |
37 | .Nm scandir_b , | |
38 | #endif | |
39 | .Nm alphasort | |
40 | .Nd scan a directory | |
41 | .Sh SYNOPSIS | |
42 | .In sys/types.h | |
43 | .In dirent.h | |
44 | .Ft int | |
45 | .Fn scandir "const char *dirname" "struct dirent ***namelist" "int \\*(lp*select\\*(rp\\*(lpstruct dirent *\\*(rp" "int \\*(lp*compar\\*(rp\\*(lpconst void *, const void *\\*(rp" | |
46 | .Ft int | |
47 | .Fn alphasort "const void *d1" "const void *d2" | |
48 | #ifdef UNIFDEF_BLOCKS | |
49 | .Ft int | |
50 | .Fn scandir_b "const char *dirname" "struct dirent ***namelist" "int \\*(lp^select\\*(rp\\*(lpstruct dirent *\\*(rp" "int \\*(lp^compar\\*(rp\\*(lpconst void *, const void *\\*(rp" | |
51 | #endif | |
52 | .Sh DESCRIPTION | |
53 | The | |
54 | .Fn scandir | |
55 | function | |
56 | reads the directory | |
57 | .Fa dirname | |
58 | and builds an array of pointers to directory | |
59 | entries using | |
60 | .Xr malloc 3 . | |
61 | It returns the number of entries in the array. | |
62 | A pointer to the array of directory entries is stored in the location | |
63 | referenced by | |
64 | .Fa namelist . | |
65 | .Pp | |
66 | The | |
67 | .Fa select | |
68 | argument is a pointer to a user supplied subroutine which is called by | |
69 | .Fn scandir | |
70 | to select which entries are to be included in the array. | |
71 | The select routine is passed a | |
72 | pointer to a directory entry and should return a non-zero | |
73 | value if the directory entry is to be included in the array. | |
74 | If | |
75 | .Fa select | |
76 | is null, then all the directory entries will be included. | |
77 | .Pp | |
78 | The | |
79 | .Fa compar | |
80 | argument is a pointer to a user supplied subroutine which is passed to | |
81 | .Xr qsort 3 | |
82 | to sort the completed array. | |
83 | If this pointer is null, the array is not sorted. | |
84 | Note that from within the | |
85 | .Fa compar | |
86 | subroutine, the two arguments are of type | |
87 | .Ft const struct dirent ** , | |
88 | so that a double-dereference is needed to access the fields in the | |
89 | .Ft dirent | |
90 | structure. | |
91 | .Pp | |
92 | The | |
93 | .Fn alphasort | |
94 | function | |
95 | is a routine which can be used for the | |
96 | .Fa compar | |
97 | argument to sort the array alphabetically. | |
98 | .Pp | |
99 | The memory allocated for the array can be deallocated with | |
100 | .Xr free 3 , | |
101 | by freeing each pointer in the array and then the array itself. | |
102 | #ifdef UNIFDEF_BLOCKS | |
103 | .Pp | |
104 | The | |
105 | .Fn scandir_b | |
106 | function works the same way as the | |
107 | .Fn scandir | |
108 | function, except that | |
109 | .Fa select | |
110 | and | |
111 | .Fa compar | |
112 | are blocks instead of subroutines. | |
113 | #endif | |
114 | .Sh DIAGNOSTICS | |
115 | Returns \-1 if the directory cannot be opened for reading or if | |
116 | .Xr malloc 3 | |
117 | cannot allocate enough memory to hold all the data structures. | |
118 | .Sh SEE ALSO | |
119 | .Xr directory 3 , | |
120 | .Xr malloc 3 , | |
121 | .Xr qsort 3 , | |
122 | .Xr dir 5 | |
123 | .Sh HISTORY | |
124 | The | |
125 | .Fn scandir | |
126 | and | |
127 | .Fn alphasort | |
128 | functions appeared in | |
129 | .Bx 4.2 . | |
130 | #ifdef UNIFDEF_BLOCKS | |
131 | The | |
132 | .Fn scandir_b | |
133 | function appeared in Mac OS X 10.6. | |
134 | #endif |