stdlib/FreeBSD/realpath.3

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  35 .\"     @(#)realpath.3  8.2 (Berkeley) 2/16/94
  36 .\" $FreeBSD: src/lib/libc/stdlib/realpath.3,v 1.13 2003/03/27 20:48:53 fjoe Exp $
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  38 .Dd February 16, 1994
  39 .Dt REALPATH 3
  40 .Os
  41 .Sh NAME
  42 .Nm realpath
  43 .Nd returns the canonicalized absolute pathname
  44 .Sh LIBRARY
  45 .Lb libc
  46 .Sh SYNOPSIS
  47 .In sys/param.h
  48 .In stdlib.h
  49 .Ft "char *"
  50 .Fn realpath "const char *pathname" "char resolved_path[PATH_MAX]"
  51 .Sh DESCRIPTION
  52 The
  53 .Fn realpath
  54 function resolves all symbolic links, extra
  55 .Dq /
  56 characters and references to
  57 .Pa /./
  58 and
  59 .Pa /../
  60 in
  61 .Fa pathname ,
  62 and copies the resulting absolute pathname into
  63 the memory referenced by
  64 .Fa resolved_path .
  65 The
  66 .Fa resolved_path
  67 argument
  68 .Em must
  69 refer to a buffer capable of storing at least
  70 .Dv PATH_MAX
  71 characters.
  72 .Pp
  73 The
  74 .Fn realpath
  75 function will resolve both absolute and relative paths
  76 and return the absolute pathname corresponding to
  77 .Fa pathname .
  78 All but the last component of
  79 .Fa pathname
  80 must exist when
  81 .Fn realpath
  82 is called.
  83 .Sh "RETURN VALUES"
  84 The
  85 .Fn realpath
  86 function returns
  87 .Fa resolved_path
  88 on success.
  89 If an error occurs,
  90 .Fn realpath
  91 returns
  92 .Dv NULL ,
  93 and
  94 .Fa resolved_path
  95 contains the pathname which caused the problem.
  96 .Sh ERRORS
  97 The function
  98 .Fn realpath
  99 may fail and set the external variable
 100 .Va errno
 101 for any of the errors specified for the library functions
 102 .Xr lstat 2 ,
 103 .Xr readlink 2
 104 and
 105 .Xr getcwd 3 .
 106 .Sh CAVEATS
 107 This implementation of
 108 .Fn realpath
 109 differs slightly from the Solaris implementation.
 110 The
 111 .Bx 4.4
 112 version always returns absolute pathnames,
 113 whereas the Solaris implementation will,
 114 under certain circumstances, return a relative
 115 .Fa resolved_path
 116 when given a relative
 117 .Fa pathname .
 118 .Sh "SEE ALSO"
 119 .Xr getcwd 3
 120 .Sh HISTORY
 121 The
 122 .Fn realpath
 123 function first appeared in
 124 .Bx 4.4 .