1.\" $NetBSD: scandir.3,v 1.14 2010/12/17 19:20:42 njoly 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.\" @(#)scandir.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd April 29, 2010 33.Dt SCANDIR 3 34.Os 35.Sh NAME 36.Nm scandir , 37.Nm alphasort 38.Nd scan a directory 39.Sh LIBRARY 40.Lb libc 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\*(lpconst struct dirent *\*(rp" "int \*(lp*compar\*(rp\*(lpconst void *, const void *\*(rp" 46.Ft int 47.Fn alphasort "const void *d1" "const void *d2" 48.Sh DESCRIPTION 49The 50.Fn scandir 51function 52reads the directory 53.Fa dirname 54and builds an array of pointers to directory 55entries using 56.Xr malloc 3 . 57It returns the number of entries in the array. 58A pointer to the array of directory entries is stored in the location 59referenced by 60.Fa namelist . 61.Pp 62The 63.Fa select 64parameter is a pointer to a user supplied subroutine which is called by 65.Fn scandir 66to select which entries are to be included in the array. 67The select routine is passed a 68pointer to a directory entry and should return a non-zero 69value if the directory entry is to be included in the array. 70If 71.Fa select 72is null, then all the directory entries will be included. 73.Pp 74The 75.Fa compar 76parameter is a pointer to a user supplied subroutine which is passed to 77.Xr qsort 3 78to sort the completed array. 79If this pointer is null, the array is not sorted. 80.Pp 81The 82.Fn alphasort 83function 84is a routine which can be used for the 85.Fa compar 86parameter to sort the array alphabetically. 87.Pp 88The memory allocated for the array can be deallocated with 89.Xr free 3 , 90by freeing each pointer in the array and then the array itself. 91.Sh DIAGNOSTICS 92Returns \-1 if the directory cannot be opened for reading or if 93.Xr malloc 3 94cannot allocate enough memory to hold all the data structures. 95.Sh SEE ALSO 96.Xr directory 3 , 97.Xr dirent 3 , 98.Xr malloc 3 , 99.Xr qsort 3 100.Sh STANDARDS 101The 102.Fn scandir 103and 104.Fn alphasort 105functions conform to 106.St -p1003.1-2008 . 107.Sh HISTORY 108The 109.Fn scandir 110and 111.Fn alphasort 112functions appeared in 113.Bx 4.2 . 114