m4/ax_normalize_path.m4

   1 # ===========================================================================
   2 #     http://www.gnu.org/software/autoconf-archive/ax_normalize_path.html
   3 # ===========================================================================
   4 #
   5 # SYNOPSIS
   6 #
   7 #   AX_NORMALIZE_PATH(VARNAME, [REFERENCE_STRING])
   8 #
   9 # DESCRIPTION
  10 #
  11 #   Perform some cleanups on the value of $VARNAME (interpreted as a path):
  12 #
  13 #     - empty paths are changed to '.'
  14 #     - trailing slashes are removed
  15 #     - repeated slashes are squeezed except a leading doubled slash '//'
  16 #       (which might indicate a networked disk on some OS).
  17 #
  18 #   REFERENCE_STRING is used to turn '/' into '\' and vice-versa: if
  19 #   REFERENCE_STRING contains some backslashes, all slashes and backslashes
  20 #   are turned into backslashes, otherwise they are all turned into slashes.
  21 #
  22 #   This makes processing of DOS filenames quite easier, because you can
  23 #   turn a filename to the Unix notation, make your processing, and turn it
  24 #   back to original notation.
  25 #
  26 #     filename='A:\FOO\\BAR\'
  27 #     old_filename="$filename"
  28 #     # Switch to the unix notation
  29 #     AX_NORMALIZE_PATH([filename], ["/"])
  30 #     # now we have $filename = 'A:/FOO/BAR' and we can process it as if
  31 #     # it was a Unix path.  For instance let's say that you want
  32 #     # to append '/subpath':
  33 #     filename="$filename/subpath"
  34 #     # finally switch back to the original notation
  35 #     AX_NORMALIZE_PATH([filename], ["$old_filename"])
  36 #     # now $filename equals to 'A:\FOO\BAR\subpath'
  37 #
  38 #   One good reason to make all path processing with the unix convention is
  39 #   that backslashes have a special meaning in many cases. For instance
  40 #
  41 #     expr 'A:\FOO' : 'A:\Foo'
  42 #
  43 #   will return 0 because the second argument is a regex in which
  44 #   backslashes have to be backslashed. In other words, to have the two
  45 #   strings to match you should write this instead:
  46 #
  47 #     expr 'A:\Foo' : 'A:\\Foo'
  48 #
  49 #   Such behavior makes DOS filenames extremely unpleasant to work with. So
  50 #   temporary turn your paths to the Unix notation, and revert them to the
  51 #   original notation after the processing. See the macro
  52 #   AX_COMPUTE_RELATIVE_PATHS for a concrete example of this.
  53 #
  54 #   REFERENCE_STRING defaults to $VARIABLE, this means that slashes will be
  55 #   converted to backslashes if $VARIABLE already contains some backslashes
  56 #   (see $thirddir below).
  57 #
  58 #     firstdir='/usr/local//share'
  59 #     seconddir='C:\Program Files\\'
  60 #     thirddir='C:\home/usr/'
  61 #     AX_NORMALIZE_PATH([firstdir])
  62 #     AX_NORMALIZE_PATH([seconddir])
  63 #     AX_NORMALIZE_PATH([thirddir])
  64 #     # $firstdir = '/usr/local/share'
  65 #     # $seconddir = 'C:\Program Files'
  66 #     # $thirddir = 'C:\home\usr'
  67 #
  68 # LICENSE
  69 #
  70 #   Copyright (c) 2008 Alexandre Duret-Lutz <adl@gnu.org>
  71 #
  72 #   This program is free software; you can redistribute it and/or modify it
  73 #   under the terms of the GNU General Public License as published by the
  74 #   Free Software Foundation; either version 2 of the License, or (at your
  75 #   option) any later version.
  76 #
  77 #   This program is distributed in the hope that it will be useful, but
  78 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  79 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  80 #   Public License for more details.
  81 #
  82 #   You should have received a copy of the GNU General Public License along
  83 #   with this program. If not, see <http://www.gnu.org/licenses/>.
  84 #
  85 #   As a special exception, the respective Autoconf Macro's copyright owner
  86 #   gives unlimited permission to copy, distribute and modify the configure
  87 #   scripts that are the output of Autoconf when processing the Macro. You
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  90 #   Macro appear in them. The GNU General Public License (GPL) does govern
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  96 #   exception to the GPL to apply to your modified version as well.
  97
  98 #serial 5
  99
 100 AU_ALIAS([ADL_NORMALIZE_PATH], [AX_NORMALIZE_PATH])
 101 AC_DEFUN([AX_NORMALIZE_PATH],
 102 [case ":[$]$1:" in
 103 # change empty paths to '.'
 104   ::) $1='.' ;;
 105 # strip trailing slashes
 106   :*[[\\/]]:) $1=`echo "[$]$1" | sed 's,[[\\/]]*[$],,'` ;;
 107   :*:) ;;
 108 esac
 109 # squeze repeated slashes
 110 case ifelse($2,,"[$]$1",$2) in
 111 # if the path contains any backslashes, turn slashes into backslashes
 112  *\\*) $1=`echo "[$]$1" | sed 's,\(.\)[[\\/]][[\\/]]*,\1\\\\,g'` ;;
 113 # if the path contains slashes, also turn backslashes into slashes
 114  *) $1=`echo "[$]$1" | sed 's,\(.\)[[\\/]][[\\/]]*,\1/,g'` ;;
 115 esac])