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.\" 3. 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. 15.\" 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 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)scandir.3 8.1 (Berkeley) 6/4/93 29.\" $FreeBSD: src/lib/libc/gen/scandir.3,v 1.3.2.5 2003/03/15 15:11:05 trhodes Exp $ 30.\" 31.Dd November 4, 2010 32.Dt SCANDIR 3 33.Os 34.Sh NAME 35.Nm scandir , 36.Nm alphasort 37.Nd scan a directory 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In sys/types.h 42.In dirent.h 43.Ft int 44.Fn scandir "const char *dirname" "struct dirent ***namelist" "int \\*(lp*select\\*(rp\\*(lpconst struct dirent *\\*(rp" "int \\*(lp*compar\\*(rp\\*(lpconst struct dirent **, const struct dirent **\\*(rp" 45.Ft int 46.Fn alphasort "const struct dirent **d1" "const struct dirent **d2" 47.Sh DESCRIPTION 48The 49.Fn scandir 50function 51reads the directory 52.Fa dirname 53and builds an array of pointers to directory 54entries using 55.Xr malloc 3 . 56It returns the number of entries in the array. 57A pointer to the array of directory entries is stored in the location 58referenced by 59.Fa namelist . 60.Pp 61The 62.Fa select 63argument is a pointer to a user supplied subroutine which is called by 64.Fn scandir 65to select which entries are to be included in the array. 66The select routine is passed a 67pointer to a directory entry and should return a non-zero 68value if the directory entry is to be included in the array. 69If 70.Fa select 71is null, then all the directory entries will be included. 72.Pp 73The 74.Fa compar 75argument is a pointer to a user supplied subroutine which is passed to 76.Xr qsort 3 77to sort the completed array. 78If this pointer is null, the array is not sorted. 79.Pp 80The 81.Fn alphasort 82function 83is a routine which can be used for the 84.Fa compar 85argument to sort the array alphabetically. 86.Pp 87The memory allocated for the array can be deallocated with 88.Xr free 3 , 89by freeing each pointer in the array and then the array itself. 90.Sh DIAGNOSTICS 91Returns \-1 if the directory cannot be opened for reading or if 92.Xr malloc 3 93cannot allocate enough memory to hold all the data structures. 94.Sh SEE ALSO 95.Xr directory 3 , 96.Xr malloc 3 , 97.Xr qsort 3 , 98.Xr dir 5 99.Sh HISTORY 100The 101.Fn scandir 102and 103.Fn alphasort 104functions appeared in 105.Bx 4.2 . 106