+# Note this deviates from the version comparison in automake
+# in that it treats 1.5 < 1.5.0, and treats 1.4.4a < 1.4-p3a
+# but this should suffice as we won't be specifying old
+# version formats or redundant trailing .0 in bootstrap.conf.
+# If we did want full compatibility then we should probably
+# use m4_version_compare from autoconf.
+sort_ver() { # sort -V is not generally available
+ ver1="$1"
+ ver2="$2"
+
+ # split on '.' and compare each component
+ i=1
+ while : ; do
+ p1=$(echo "$ver1" | cut -d. -f$i)
+ p2=$(echo "$ver2" | cut -d. -f$i)
+ if [ ! "$p1" ]; then
+ echo "$1 $2"
+ break
+ elif [ ! "$p2" ]; then
+ echo "$2 $1"
+ break
+ elif [ ! "$p1" = "$p2" ]; then
+ if [ "$p1" -gt "$p2" ] 2>/dev/null; then # numeric comparison
+ echo "$2 $1"
+ elif [ "$p2" -gt "$p1" ] 2>/dev/null; then # numeric comparison
+ echo "$1 $2"
+ else # numeric, then lexicographic comparison
+ lp=$(printf "$p1\n$p2\n" | LANG=C sort -n | tail -n1)
+ if [ "$lp" = "$p2" ]; then
+ echo "$1 $2"
+ else
+ echo "$2 $1"
+ fi
+ fi
+ break
+ fi
+ i=$(($i+1))
+ done
+}
+
+get_version() {
+ app=$1
+
+ $app --version >/dev/null 2>&1 || return 1
+
+ $app --version 2>&1 |
+ sed -n '# Move version to start of line.
+ s/.*[v ]\([0-9]\)/\1/
+
+ # Skip lines that do not start with version.
+ /^[0-9]/!d
+
+ # Remove characters after the version.
+ s/[^.a-z0-9-].*//
+
+ # The first component must be digits only.
+ s/^\([0-9]*\)[a-z-].*/\1/
+
+ #the following essentially does s/5.005/5.5/
+ s/\.0*\([1-9]\)/.\1/g
+ p
+ q'
+}
+
+check_versions() {
+ ret=0
+
+ while read app req_ver; do
+ # We only need libtoolize from the libtool package.
+ if test "$app" = libtool; then
+ app=libtoolize
+ fi
+ # Exempt git if --no-git is in effect.
+ if test "$app" = git; then
+ $use_git || continue
+ fi
+ # Honor $APP variables ($TAR, $AUTOCONF, etc.)
+ appvar=`echo $app | tr '[a-z]-' '[A-Z]_'`
+ test "$appvar" = TAR && appvar=AMTAR
+ eval "app=\${$appvar-$app}"
+ inst_ver=$(get_version $app)
+ if [ ! "$inst_ver" ]; then
+ echo "$me: Error: '$app' not found" >&2
+ ret=1
+ elif [ ! "$req_ver" = "-" ]; then
+ latest_ver=$(sort_ver $req_ver $inst_ver | cut -d' ' -f2)
+ if [ ! "$latest_ver" = "$inst_ver" ]; then
+ echo "$me: Error: '$app' version == $inst_ver is too old" >&2
+ echo " '$app' version >= $req_ver is required" >&2
+ ret=1
+ fi
+ fi
+ done
+
+ return $ret
+}
+
+print_versions() {
+ echo "Program Min_version"
+ echo "----------------------"
+ printf %s "$buildreq"
+ echo "----------------------"
+ # can't depend on column -t
+}
+
+use_libtool=0
+# We'd like to use grep -E, to see if any of LT_INIT,
+# AC_PROG_LIBTOOL, AM_PROG_LIBTOOL is used in configure.ac,
+# but that's not portable enough (e.g., for Solaris).
+grep '^[ ]*A[CM]_PROG_LIBTOOL' configure.ac >/dev/null \
+ && use_libtool=1
+grep '^[ ]*LT_INIT' configure.ac >/dev/null \
+ && use_libtool=1
+if test $use_libtool = 1; then
+ find_tool LIBTOOLIZE glibtoolize libtoolize
+fi
+
+if ! printf "$buildreq" | check_versions; then
+ echo >&2
+ if test -f README-prereq; then
+ echo "$0: See README-prereq for how to get the prerequisite programs" >&2
+ else
+ echo "$0: Please install the prerequisite programs" >&2
+ fi
+ exit 1
+fi
+