Snippet of code that provides relocatability to shell scripts.

1 files changed, 132 insertions, 0 deletions

diff --git a/build-aux/relocatable.sh.in b/build-aux/relocatable.sh.in
new file mode 100644
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+++ b/build-aux/relocatable.sh.in
@@ -0,0 +1,132 @@
+# The functions in this file provide support for relocatability of
+# shell scripts.  They should be included near the beginning of each
+# shell script in a relocatable program, by adding @relocatable_sh@
+# and causing the script to be expanded with AC_CONFIG_FILES.  A
+# small amount of additional code must be added and adapted to the
+# package by hand; see doc/relocatable-maint.texi (in Gnulib) for
+# details.
+#
+# Copyright (C) 2003, 2005-2007 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+
+# func_tmpdir
+# creates a temporary directory.
+# Sets variable
+# - tmp             pathname of freshly created temporary directory
+func_tmpdir ()
+{
+  # Use the environment variable TMPDIR, falling back to /tmp. This allows
+  # users to specify a different temporary directory, for example, if their
+  # /tmp is filled up or too small.
+  : ${TMPDIR=/tmp}
+  {
+    # Use the mktemp program if available. If not available, hide the error
+    # message.
+    tmp=`(umask 077 && mktemp -d "$TMPDIR/glXXXXXX") 2>/dev/null` &&
+    test -n "$tmp" && test -d "$tmp"
+  } ||
+  {
+    # Use a simple mkdir command. It is guaranteed to fail if the directory
+    # already exists.  $RANDOM is bash specific and expands to empty in shells
+    # other than bash, ksh and zsh.  Its use does not increase security;
+    # rather, it minimizes the probability of failure in a very cluttered /tmp
+    # directory.
+    tmp=$TMPDIR/gl$$-$RANDOM
+    (umask 077 && mkdir "$tmp")
+  } ||
+  {
+    echo "$0: cannot create a temporary directory in $TMPDIR" >&2
+    { (exit 1); exit 1; }
+  }
+}
+
+# Support for relocatability.
+func_find_curr_installdir ()
+{
+  # Determine curr_installdir, even taking into account symlinks.
+  curr_executable="$0"
+  case "$curr_executable" in
+    */* | *\\*) ;;
+    *) # Need to look in the PATH.
+      if test "${PATH_SEPARATOR+set}" != set; then
+        func_tmpdir
+        { echo "#! /bin/sh"; echo "exit 0"; } > "$tmp"/conf.sh
+        chmod +x "$tmp"/conf.sh
+        if (PATH="/nonexistent;$tmp"; conf.sh) >/dev/null 2>&1; then
+          PATH_SEPARATOR=';'
+        else
+          PATH_SEPARATOR=:
+        fi
+        rm -rf "$tmp"
+      fi
+      save_IFS="$IFS"; IFS="$PATH_SEPARATOR"
+      for dir in $PATH; do
+        IFS="$save_IFS"
+        test -z "$dir" && dir=.
+        for exec_ext in ''; do
+          if test -f "$dir/$curr_executable$exec_ext"; then
+            curr_executable="$dir/$curr_executable$exec_ext"
+            break 2
+          fi
+        done
+      done
+      IFS="$save_IFS"
+      ;;
+  esac
+  # Make absolute.
+  case "$curr_executable" in
+    /* | ?:/* | ?:\\*) ;;
+    *) curr_executable=`pwd`/"$curr_executable" ;;
+  esac
+  # Resolve symlinks.
+  sed_dirname='s,/[^/]*$,,'
+  sed_linkdest='s,^.* -> \(.*\),\1,p'
+  while : ; do
+    lsline=`LC_ALL=C ls -l "$curr_executable"`
+    case "$lsline" in
+      *" -> "*)
+        linkdest=`echo "$lsline" | sed -n -e "$sed_linkdest"`
+        case "$linkdest" in
+          /* | ?:/* | ?:\\*) curr_executable="$linkdest" ;;
+          *) curr_executable=`echo "$curr_executable" | sed -e "$sed_dirname"`/"$linkdest" ;;
+        esac ;;
+      *) break ;;
+    esac
+  done
+  curr_installdir=`echo "$curr_executable" | sed -e 's,/[^/]*$,,'`
+  # Canonicalize.
+  curr_installdir=`cd "$curr_installdir" && pwd`
+}
+func_find_prefixes ()
+{
+  # Compute the original/current installation prefixes by stripping the
+  # trailing directories off the original/current installation directories.
+  orig_installprefix="$orig_installdir"
+  curr_installprefix="$curr_installdir"
+  while true; do
+    orig_last=`echo "$orig_installprefix" | sed -n -e 's,^.*/\([^/]*\)$,\1,p'`
+    curr_last=`echo "$curr_installprefix" | sed -n -e 's,^.*/\([^/]*\)$,\1,p'`
+    if test -z "$orig_last" || test -z "$curr_last"; then
+      break
+    fi
+    if test "$orig_last" != "$curr_last"; then
+      break
+    fi
+    orig_installprefix=`echo "$orig_installprefix" | sed -e 's,/[^/]*$,,'`
+    curr_installprefix=`echo "$curr_installprefix" | sed -e 's,/[^/]*$,,'`
+  done
+}