--- a
+++ b/hooks/pre-lock.tmpl
@@ -0,0 +1,95 @@
+#!/bin/sh
+
+# PRE-LOCK HOOK
+#
+# The pre-lock hook is invoked before an exclusive lock is
+# created.  Subversion runs this hook by invoking a program 
+# (script, executable, binary, etc.) named 'pre-lock' (for which
+# this file is a template), with the following ordered arguments:
+#
+#   [1] REPOS-PATH   (the path to this repository)
+#   [2] PATH         (the path in the repository about to be locked)
+#   [3] USER         (the user creating the lock)
+#   [4] COMMENT      (the comment of the lock)
+#   [5] STEAL-LOCK   (1 if the user is trying to steal the lock, else 0)
+#
+# If the hook program outputs anything on stdout, the output string will
+# be used as the lock token for this lock operation.  If you choose to use
+# this feature, you must guarantee the tokens generated are unique across
+# the repository each time.
+#
+# If the hook program exits with success, the lock is created; but
+# if it exits with failure (non-zero), the lock action is aborted
+# and STDERR is returned to the client.
+#
+# The default working directory for the invocation is undefined, so
+# the program should set one explicitly if it cares.
+#
+# On a Unix system, the normal procedure is to have 'pre-lock'
+# invoke other programs to do the real work, though it may do the
+# work itself too.
+#
+# Note that 'pre-lock' must be executable by the user(s) who will
+# invoke it (typically the user httpd runs as), and that user must
+# have filesystem-level permission to access the repository.
+#
+# On a Windows system, you should name the hook program
+# 'pre-lock.bat' or 'pre-lock.exe',
+# but the basic idea is the same.
+#
+# The hook program runs in an empty environment, unless the server is
+# explicitly configured otherwise.  For example, a common problem is for
+# the PATH environment variable to not be set to its usual value, so
+# that subprograms fail to launch unless invoked via absolute path.
+# If you're having unexpected problems with a hook program, the
+# culprit may be unusual (or missing) environment variables.
+#
+# CAUTION:
+# For security reasons, you MUST always properly quote arguments when
+# you use them, as those arguments could contain whitespace or other
+# problematic characters. Additionally, you should delimit the list
+# of options with "--" before passing the arguments, so malicious
+# clients cannot bootleg unexpected options to the commands your
+# script aims to execute.
+# For similar reasons, you should also add a trailing @ to URLs which
+# are passed to SVN commands accepting URLs with peg revisions.
+#
+# Here is an example hook script, for a Unix /bin/sh interpreter.
+# For more examples and pre-written hooks, see those in
+# the Subversion repository at
+# http://svn.apache.org/repos/asf/subversion/trunk/tools/hook-scripts/ and
+# http://svn.apache.org/repos/asf/subversion/trunk/contrib/hook-scripts/
+
+
+REPOS="$1"
+PATH="$2"
+USER="$3"
+COMMENT="$4"
+STEAL="$5"
+
+# If a lock exists and is owned by a different person, don't allow it
+# to be stolen (e.g., with 'svn lock --force ...').
+
+# (Maybe this script could send email to the lock owner?)
+SVNLOOK=/usr/local/bin/svnlook
+GREP=/bin/grep
+SED=/bin/sed
+
+LOCK_OWNER=`$SVNLOOK lock "$REPOS" "$PATH" | \
+            $GREP '^Owner: ' | $SED 's/Owner: //'`
+
+# If we get no result from svnlook, there's no lock, allow the lock to
+# happen:
+if [ "$LOCK_OWNER" = "" ]; then
+  exit 0
+fi
+
+# If the person locking matches the lock's owner, allow the lock to
+# happen:
+if [ "$LOCK_OWNER" = "$USER" ]; then
+  exit 0
+fi
+
+# Otherwise, we've got an owner mismatch, so return failure:
+echo "Error: $PATH already locked by ${LOCK_OWNER}." 1>&2
+exit 1