getver: rewrite from perl to shell+awk #535

People are more familiar with shell than perl at this point.
Fixes #535.

4 files changed, 50 insertions, 47 deletions

diff --git a/config/Makefile.am b/config/Makefile.am
index 6416dda..c5a8bb5 100644
--- a/config/Makefile.am
+++ b/config/Makefile.am
@@ -1,5 +1,5 @@
 ## Process this file with automake to produce Makefile.in -*-Makefile-*-
-EXTRA_DIST = gdlib.pc.cmake gdlib.pc.in getlib.sh getver.pl
+EXTRA_DIST = gdlib.pc.cmake gdlib.pc.in getlib.sh getver.sh
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = gdlib.pc
diff --git a/config/getlib.sh b/config/getlib.sh
index 4835cf6..5070e30 100755
--- a/config/getlib.sh
+++ b/config/getlib.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-GETVER="${0%/*}/getver.pl"
+GETVER="${0%/*}/getver.sh"
 GDLIB_MAJOR=$("${GETVER}" MAJOR)
 GDLIB_MINOR=$("${GETVER}" MINOR)
 GDLIB_REVISION=$("${GETVER}" RELEASE)
diff --git a/config/getver.pl b/config/getver.pl
deleted file mode 100755
index 52f1b58..0000000
--- a/config/getver.pl
+++ /dev/null
@@ -1,45 +0,0 @@
-#!/usr/bin/env perl
-
-# Simple script to extract the version number parts from src/gd.h.  If
-# called with the middle word of the version macro, it prints the
-# value of that macro.  If called with no argument, it outputs a
-# human-readable version string.  This must be run in the project
-# root.  It is used by configure.ac and docs/naturaldocs/run_docs.sh.
-
-use strict;
-
-use FindBin;
-
-my $key = shift;
-my @version_parts = ();
-my $dir = $FindBin::Bin;
-
-open FH, "<$dir/../src/gd.h"   # old-style filehandle for max. portability
-  or die "Unable to open 'gd.h' for reading.\n";
-
-while(<FH>) {
-  next unless m{version605b5d1778};
-  next unless /^#define\s+GD_([A-Z0-9]+)_VERSION+\s+(\S+)/;
-  my ($lk, $lv) = ($1, $2);
-  if ($lk eq $key) {
-    chomp $lv;
-    $lv =~ s/"//g;
-
-    print $lv;   # no newline
-    exit(0);    # success!
-  }
-
-  push @version_parts, $lv if (!$key);
-}
-
-close(FH);
-
-if (scalar @version_parts == 4) {
-  my $result = join(".", @version_parts[0..2]);
-  $result .= $version_parts[3];
-  $result =~ s/"//g;
-  print $result;
-  exit(0);
-}
-
-exit(1);        # failure
diff --git a/config/getver.sh b/config/getver.sh
new file mode 100755
index 0000000..589802f
--- /dev/null
+++ b/config/getver.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+# Simple script to extract the version number parts from src/gd.h.  If
+# called with the middle word of the version macro, it prints the
+# value of that macro.  If called with no argument, it outputs a
+# human-readable version string.  This must be run in the project
+# root.  It is used by configure.ac and docs/naturaldocs/run_docs.sh.
+
+TOPDIR="${0%/*}/.."
+HEADER="${TOPDIR}/src/gd.h"
+SENTINEL="/*version605b5d1778*/"
+
+getpart() {
+	awk -vfield="GD_${1}_VERSION" -vsentinel="${SENTINEL}" '
+		$1 == "#define" && $2 == field && $NF == sentinel {
+			gsub(/^"/, "", $3)
+			gsub(/"$/, "", $3)
+			print $3
+		}
+	' "${HEADER}"
+}
+
+case $# in
+0)
+	printf '%s.%s.%s%s\n' \
+		$(getpart MAJOR) \
+		$(getpart MINOR) \
+		$(getpart RELEASE) \
+		$(getpart EXTRA)
+	;;
+1)
+	case $1 in
+	MAJOR|MINOR|RELEASE|EXTRA)
+		part=$(getpart "$1")
+		if [ -n "${part}" ]; then
+			printf '%s' "${part}"
+		fi
+		;;
+	*)
+		exit 1
+		;;
+	esac
+	;;
+*)
+	echo "$0: error: script takes at most 1 arg"
+	exit 1
+	;;
+esac