gen/FreeBSD/dirname.3

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   2 .\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
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  27 .\" $OpenBSD: dirname.3,v 1.9 2000/04/18 03:01:25 aaron Exp $
  28 .\" $FreeBSD: src/lib/libc/gen/dirname.3,v 1.8 2004/07/02 23:52:10 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 part 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 .Fa path .
  48 Any trailing
  49 .Sq \&/
  50 characters are not counted as part of the directory
  51 name.
  52 If
  53 .Fa 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 .Fa 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 The
  82 .Fn dirname
  83 function
  84 returns a pointer to internal static storage space that will be overwritten
  85 by subsequent calls (each function has its own separate storage).
  86 .Pp
  87 Other vendor implementations of
  88 .Fn dirname
  89 may modify the contents of the string passed to
  90 .Fn dirname ;
  91 this should be taken into account when writing code which calls this function
  92 if portability is desired.
  93 .Sh SEE ALSO
  94 .Xr basename 1 ,
  95 .Xr dirname 1 ,
  96 .Xr basename 3
  97 .Sh STANDARDS
  98 The
  99 .Fn dirname
 100 function conforms to
 101 .St -xpg4.2 .
 102 .Sh HISTORY
 103 The
 104 .Fn dirname
 105 function first appeared in
 106 .Ox 2.2
 107 and
 108 .Fx 4.2 .
 109 .Sh AUTHORS
 110 .An "Todd C. Miller" Aq Todd.Miller@courtesan.com