123 lines
3.7 KiB
Groff
123 lines
3.7 KiB
Groff
.\" $NetBSD: scandir.3,v 1.16 2016/12/17 10:25:49 wiz Exp $
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.\"
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.\" Copyright (c) 1983, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)scandir.3 8.1 (Berkeley) 6/4/93
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.\"
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.Dd December 15, 2016
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.Dt SCANDIR 3
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.Os
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.Sh NAME
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.Nm scandir ,
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.Nm alphasort
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.Nd scan a directory
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In sys/types.h
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.In dirent.h
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.Ft int
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.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"
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.Ft int
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.Fn alphasort "const struct dirent **d1" "const struct dirent **d2"
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.Sh DESCRIPTION
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The
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.Fn scandir
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function
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reads the directory
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.Fa dirname
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and builds an array of pointers to directory
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entries using
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.Xr malloc 3 .
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It returns the number of entries in the array.
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A pointer to the array of directory entries is stored in the location
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referenced by
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.Fa namelist .
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.Pp
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The
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.Fa select
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parameter is a pointer to a user supplied subroutine which is called by
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.Fn scandir
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to select which entries are to be included in the array.
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The select routine is passed a
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pointer to a directory entry and should return a non-zero
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value if the directory entry is to be included in the array.
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If
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.Fa select
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is null, then all the directory entries will be included.
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.Pp
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The
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.Fa compar
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parameter is a pointer to a user supplied subroutine which is passed to
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.Xr qsort 3
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to sort the completed array.
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If this pointer is null, the array is not sorted.
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.Pp
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The
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.Fn alphasort
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function
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is a routine which can be used for the
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.Fa compar
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parameter to sort the array alphabetically.
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.Pp
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The memory allocated for the array can be deallocated with
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.Xr free 3 ,
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by freeing each pointer in the array and then the array itself.
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.Sh DIAGNOSTICS
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Returns \-1 if the directory cannot be opened for reading or if
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.Xr malloc 3
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cannot allocate enough memory to hold all the data structures.
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.Sh SEE ALSO
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.Xr directory 3 ,
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.Xr dirent 3 ,
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.Xr malloc 3 ,
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.Xr qsort 3
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.Sh STANDARDS
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The
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.Fn scandir
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and
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.Fn alphasort
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functions conform to
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.St -p1003.1-2008 .
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.Sh HISTORY
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The
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.Fn scandir
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and
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.Fn alphasort
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functions appeared in
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.Bx 4.2 .
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.Pp
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They were changed in
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.Nx 8.0
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to use
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.Dq struct dirent **
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instead of
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.Dq void *
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for the comparison function, including
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.Fn alphasort .
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