sample GIT pre-commit hook

contrib/hooks/git-pre-commit-hook.pl

@@ -0,0 +1,72 @@
+#!/usr/bin/perl
+#
+# Pre-commit hook for running checkstyle on changed Java sources
+#
+# To use this you need:
+# 1. checkstyle's jar file somewhere
+# 2. a checkstyle XML check file somewhere
+# 3. To configure git:
+#   * git config --add checkstyle.jar <location of jar>
+#   * git config --add checkstyle.checkfile <location of checkfile>
+#   * git config --add java.command <path to java executale> [optional
+#     defaults to assuming it's in your path]
+# 4. Put this in your .git/hooks directory as pre-commit
+#
+# Now, when you commit, you will be disallowed from doing so
+# until you pass your checkstyle checks.
+
+$command = "git-diff-index --cached HEAD 2>&1 | sed 's/^:.*     //' | uniq";
+open (FILES,$command . "|") || die "Cannot run '$command': $!\n";
+
+$CONFIG_CHECK_FILE = "checkstyle.checkfile";
+$CONFIG_JAR = "checkstyle.jar";
+$CONFIG_JAVA = "java.command";
+
+$check_file = `git config --get $CONFIG_CHECK_FILE`;
+$checkstyle_jar = `git config --get $CONFIG_JAR`;
+$java_command = `git config --get $CONFIG_JAVA`;
+
+if (!$check_file || !$checkstyle_jar)
+{
+   die "You must configure checkstyle in your git config:\n"
+   . "\t$CONFIG_CHECK_FILE - path to your checkstyle.xml file\n"
+   . "\t$CONFIG_JAR - path to your checkstyle jar file\n"
+   . "\t$CONFIG_JAVA - path to your java executable (optional)\n"
+   ;
+}
+
+$java_command = "java" if (!$java_command);
+
+chomp $check_file;
+chomp $checkstyle_jar;
+chomp $java_command;
+
+$command = "$java_command -jar $checkstyle_jar -c $check_file";
+
+@java_files = ();
+
+foreach (<FILES>)
+{
+   chomp;
+   next if (!(/\.java$/));
+   push @java_files,$_;
+   $command .= " ";
+   $command .= $_;
+}
+if ($#java_files >= 0)
+{
+   if (&run_and_log_system ($command))
+   {
+       print STDERR "Commit aborted.\n";
+       exit -1;
+   }
+}
+
+exit 0;
+
+sub run_and_log_system
+{
+   ($cmd) = @_;
+
+   system $cmd;
+}