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 scandir_b "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" 46.Ft int 47.Fn alphasort "const struct dirent **d1" "const struct dirent **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 64argument 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 76argument 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 86argument to sort the array alphabetically using 87.Xr strcoll 3 . 88.Pp 89The memory allocated for the array can be deallocated with 90.Xr free 3 , 91by freeing each pointer in the array and then the array itself. 92.Pp 93The 94.Fn scandir_b 95function behaves in the same way as 96.Fn scandir , 97but takes blocks as arguments instead of function pointers and calls 98.Fn qsort_b 99rather than 100.Fn qsort . 101.Sh DIAGNOSTICS 102Returns \-1 if the directory cannot be opened for reading or if 103.Xr malloc 3 104cannot allocate enough memory to hold all the data structures. 105.Sh SEE ALSO 106.Xr directory 3 , 107.Xr malloc 3 , 108.Xr qsort 3 , 109.Xr strcoll 3 , 110.Xr dir 5 111.Sh HISTORY 112The 113.Fn scandir 114and 115.Fn alphasort 116functions appeared in 117.Bx 4.2 . 118