gen/dirname.3

   1 .\"
   2 .\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
   3 .\" All rights reserved.
   4 .\"
   5 .\" Redistribution and use in source and binary forms, with or without
   6 .\" modification, are permitted provided that the following conditions
   7 .\" are met:
   8 .\" 1. Redistributions of source code must retain the above copyright
   9 .\"    notice, this list of conditions and the following disclaimer.
  10 .\" 2. Redistributions in binary form must reproduce the above copyright
  11 .\"    notice, this list of conditions and the following disclaimer in the
  12 .\"    documentation and/or other materials provided with the distribution.
  13 .\" 3. The name of the author may not be used to endorse or promote products
  14 .\"    derived from this software without specific prior written permission.
  15 .\"
  16 .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  17 .\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  18 .\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  19 .\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20 .\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21 .\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22 .\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23 .\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24 .\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25 .\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 .\"
  27 .\" $OpenBSD: dirname.3,v 1.9 2000/04/18 03:01:25 aaron Exp $
  28 .\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.4 2001/10/01 16:08:50 ru Exp $
  29 .\"
  30 .Dd August 17, 1997
  31 .Dt DIRNAME 3
  32 .Os
  33 .Sh NAME
  34 .Nm dirname
  35 .Nd extract the directory portition of a pathname
  36 .Sh SYNOPSIS
  37 .In libgen.h
  38 .Ft char *
  39 .Fn dirname "const char *path"
  40 .Sh DESCRIPTION
  41 The
  42 .Fn dirname
  43 function
  44 is the converse of
  45 .Xr basename 3 ;
  46 it returns a pointer to the parent directory of the pathname pointed to by
  47 .Ar path .
  48 Any trailing
  49 .Sq \&/
  50 characters are not counted as part of the directory
  51 name.
  52 If
  53 .Ar path
  54 is a null pointer, the empty string, or contains no
  55 .Sq \&/
  56 characters,
  57 .Fn dirname
  58 returns a pointer to the string
  59 .Qq \&. ,
  60 signifying the current directory.
  61 .Sh RETURN VALUES
  62 On successful completion,
  63 .Fn dirname
  64 returns a pointer to the parent directory of
  65 .Ar path .
  66 .Pp
  67 If
  68 .Fn dirname
  69 fails, a null pointer is returned and the global variable
  70 .Va errno
  71 is set to indicate the error.
  72 .Sh ERRORS
  73 The following error codes may be set in
  74 .Va errno :
  75 .Bl -tag -width Er
  76 .It Bq Er ENAMETOOLONG
  77 The path component to be returned was larger than
  78 .Dv MAXPATHLEN .
  79 .El
  80 .Sh WARNINGS
  81 .Fn dirname
  82 returns a pointer to internal static storage space that will be overwritten
  83 by subsequent calls (each function has its own separate storage).
  84 .Pp
  85 Other vendor implementations of
  86 .Fn dirname
  87 may modify the contents of the string passed to
  88 .Fn dirname ;
  89 this should be taken into account when writing code which calls this function
  90 if portability is desired.
  91 .Sh SEE ALSO
  92 .Xr basename 1 ,
  93 .Xr dirname 1 ,
  94 .Xr basename 3
  95 .Sh STANDARDS
  96 The
  97 .Fn dirname
  98 function conforms to
  99 .St -xpg4.2 .
 100 .Sh HISTORY
 101 The
 102 .Fn dirname
 103 function first appeared in
 104 .Ox 2.2
 105 and
 106 .Fx 4.2 .
 107 .Sh AUTHORS
 108 Todd C. Miller <Todd.Miller@courtesan.com>