1# The functions in this file provide support for relocatability of
2# shell scripts.  They should be included near the beginning of each
3# shell script in a relocatable program, by adding @relocatable_sh@
4# and causing the script to be expanded with AC_CONFIG_FILES.  A
5# small amount of additional code must be added and adapted to the
6# package by hand; see doc/relocatable-maint.texi (in Gnulib) for
7# details.
8#
9# Copyright (C) 2003, 2005-2007 Free Software Foundation, Inc.
10#
11# This program is free software: you can redistribute it and/or modify
12# it under the terms of the GNU General Public License as published by
13# the Free Software Foundation; either version 3 of the License, or
14# (at your option) any later version.
15#
16# This program is distributed in the hope that it will be useful,
17# but WITHOUT ANY WARRANTY; without even the implied warranty of
18# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19# GNU General Public License for more details.
20#
21# You should have received a copy of the GNU General Public License
22# along with this program.  If not, see <http://www.gnu.org/licenses/>.
23#
24
25# func_tmpdir
26# creates a temporary directory.
27# Sets variable
28# - tmp             pathname of freshly created temporary directory
29func_tmpdir ()
30{
31  # Use the environment variable TMPDIR, falling back to /tmp. This allows
32  # users to specify a different temporary directory, for example, if their
33  # /tmp is filled up or too small.
34  : ${TMPDIR=/tmp}
35  {
36    # Use the mktemp program if available. If not available, hide the error
37    # message.
38    tmp=`(umask 077 && mktemp -d "$TMPDIR/glXXXXXX") 2>/dev/null` &&
39    test -n "$tmp" && test -d "$tmp"
40  } ||
41  {
42    # Use a simple mkdir command. It is guaranteed to fail if the directory
43    # already exists.  $RANDOM is bash specific and expands to empty in shells
44    # other than bash, ksh and zsh.  Its use does not increase security;
45    # rather, it minimizes the probability of failure in a very cluttered /tmp
46    # directory.
47    tmp=$TMPDIR/gl$$-$RANDOM
48    (umask 077 && mkdir "$tmp")
49  } ||
50  {
51    echo "$0: cannot create a temporary directory in $TMPDIR" >&2
52    { (exit 1); exit 1; }
53  }
54}
55
56# Support for relocatability.
57func_find_curr_installdir ()
58{
59  # Determine curr_installdir, even taking into account symlinks.
60  curr_executable="$0"
61  case "$curr_executable" in
62    */* | *\\*) ;;
63    *) # Need to look in the PATH.
64      if test "${PATH_SEPARATOR+set}" != set; then
65        func_tmpdir
66        { echo "#! /bin/sh"; echo "exit 0"; } > "$tmp"/conf.sh
67        chmod +x "$tmp"/conf.sh
68        if (PATH="/nonexistent;$tmp"; conf.sh) >/dev/null 2>&1; then
69          PATH_SEPARATOR=';'
70        else
71          PATH_SEPARATOR=:
72        fi
73        rm -rf "$tmp"
74      fi
75      save_IFS="$IFS"; IFS="$PATH_SEPARATOR"
76      for dir in $PATH; do
77        IFS="$save_IFS"
78        test -z "$dir" && dir=.
79        for exec_ext in ''; do
80          if test -f "$dir/$curr_executable$exec_ext"; then
81            curr_executable="$dir/$curr_executable$exec_ext"
82            break 2
83          fi
84        done
85      done
86      IFS="$save_IFS"
87      ;;
88  esac
89  # Make absolute.
90  case "$curr_executable" in
91    /* | ?:/* | ?:\\*) ;;
92    *) curr_executable=`pwd`/"$curr_executable" ;;
93  esac
94  # Resolve symlinks.
95  sed_dirname='s,/[^/]*$,,'
96  sed_linkdest='s,^.* -> \(.*\),\1,p'
97  while : ; do
98    lsline=`LC_ALL=C ls -l "$curr_executable"`
99    case "$lsline" in
100      *" -> "*)
101        linkdest=`echo "$lsline" | sed -n -e "$sed_linkdest"`
102        case "$linkdest" in
103          /* | ?:/* | ?:\\*) curr_executable="$linkdest" ;;
104          *) curr_executable=`echo "$curr_executable" | sed -e "$sed_dirname"`/"$linkdest" ;;
105        esac ;;
106      *) break ;;
107    esac
108  done
109  curr_installdir=`echo "$curr_executable" | sed -e 's,/[^/]*$,,'`
110  # Canonicalize.
111  curr_installdir=`cd "$curr_installdir" && pwd`
112}
113func_find_prefixes ()
114{
115  # Compute the original/current installation prefixes by stripping the
116  # trailing directories off the original/current installation directories.
117  orig_installprefix="$orig_installdir"
118  curr_installprefix="$curr_installdir"
119  while true; do
120    orig_last=`echo "$orig_installprefix" | sed -n -e 's,^.*/\([^/]*\)$,\1,p'`
121    curr_last=`echo "$curr_installprefix" | sed -n -e 's,^.*/\([^/]*\)$,\1,p'`
122    if test -z "$orig_last" || test -z "$curr_last"; then
123      break
124    fi
125    if test "$orig_last" != "$curr_last"; then
126      break
127    fi
128    orig_installprefix=`echo "$orig_installprefix" | sed -e 's,/[^/]*$,,'`
129    curr_installprefix=`echo "$curr_installprefix" | sed -e 's,/[^/]*$,,'`
130  done
131}
132