1.\" $OpenBSD: scandir.3,v 1.10 2010/03/26 19:30:40 jmc Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.Dd $Mdocdate: March 26 2010 $ 31.Dt SCANDIR 3 32.Os 33.Sh NAME 34.Nm scandir , 35.Nm alphasort 36.Nd scan a directory 37.Sh SYNOPSIS 38.Fd #include <sys/types.h> 39.Fd #include <dirent.h> 40.Ft int 41.Fn scandir "const char *dirname" "struct dirent ***namelist" "int \*(lp*select\*(rp\*(lpstruct dirent *\*(rp" "int \*(lp*compar\*(rp\*(lpconst void *, const void *\*(rp" 42.Ft int 43.Fn alphasort "const void *d1" "const void *d2" 44.Sh DESCRIPTION 45The 46.Fn scandir 47function reads the directory 48.Fa dirname 49and builds an array of pointers to directory 50entries using 51.Xr malloc 3 . 52It returns the number of entries in the array. 53A pointer to the array of directory entries is stored in the location 54referenced by 55.Fa namelist . 56.Pp 57The 58.Fa select 59parameter is a pointer to a user-supplied subroutine which is called by 60.Fn scandir 61to select which entries are to be included in the array. 62The select routine is passed a 63pointer to a directory entry and should return a non-zero 64value if the directory entry is to be included in the array. 65If 66.Fa select 67is 68.Dv NULL , 69then all directory entries will be included. 70.Pp 71The 72.Fa compar 73parameter is a pointer to a user-supplied subroutine which is passed to 74.Xr qsort 3 75to sort the completed array. 76If this pointer is 77.Dv NULL , 78the array is not sorted. 79.Pp 80The 81.Fn alphasort 82function is a routine which can be used for the 83.Fa compar 84parameter to sort the array alphabetically. 85.Pp 86The memory allocated for the array can be deallocated with 87.Xr free 3 , 88by freeing each pointer in the array and then the array itself. 89.Sh DIAGNOSTICS 90Returns \-1 if the directory cannot be opened for reading or if 91.Xr malloc 3 92cannot allocate enough memory to hold all the data structures. 93.Sh SEE ALSO 94.Xr directory 3 , 95.Xr malloc 3 , 96.Xr qsort 3 , 97.Xr dir 5 98.Sh HISTORY 99The 100.Fn scandir 101and 102.Fn alphasort 103functions appeared in 104.Bx 4.2 . 105