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. 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.\" $FreeBSD$ 30.\" 31.Dd January 3, 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 dirent.h 42.Ft int 43.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" 44.Ft int 45.Fn alphasort "const struct dirent **d1" "const struct dirent **d2" 46.Sh DESCRIPTION 47The 48.Fn scandir 49function 50reads the directory 51.Fa dirname 52and builds an array of pointers to directory 53entries using 54.Xr malloc 3 . 55It returns the number of entries in the array. 56A pointer to the array of directory entries is stored in the location 57referenced by 58.Fa namelist . 59.Pp 60The 61.Fa select 62argument is a pointer to a user supplied subroutine which is called by 63.Fn scandir 64to select which entries are to be included in the array. 65The select routine is passed a 66pointer to a directory entry and should return a non-zero 67value if the directory entry is to be included in the array. 68If 69.Fa select 70is null, then all the directory entries will be included. 71.Pp 72The 73.Fa compar 74argument is a pointer to a user supplied subroutine which is passed to 75.Xr qsort 3 76to sort the completed array. 77If this pointer is null, the array is not sorted. 78.Pp 79The 80.Fn alphasort 81function 82is a routine which can be used for the 83.Fa compar 84argument to sort the array alphabetically using 85.Xr strcoll 3 . 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.Xr strcoll 3 100.Sh HISTORY 101The 102.Fn scandir 103and 104.Fn alphasort 105functions appeared in 106.Bx 4.2 . 107