Initial lockfile support

1 files changed, 50 insertions, 2 deletions

diff --git a/lib/httracker/functions b/lib/httracker/functions
index 8e8964e..e3c81c4 100644
--- a/lib/httracker/functions
+++ b/lib/httracker/functions
@@ -109,12 +109,60 @@ function httracker_setup_folders {
 }
 
 # Set basic environment
-function httracker_set_env {
+function httracker_initialize {
   source `dirname $0`/config || exit 1
 
   # Create folders
   httracker_setup_folders
+
+  # Lockfile
+  LOCKFILE="${TMP}/`basename $0`.lock"
+  httracker_check_lockfile
+  httracker_set_lockfile
+}
+
+# Cleanup environment
+function httracker_teardown {
+  httracker_unset_lockfile
+  rm -rf $URLS
+}
+
+# Create lockfile
+function httracker_set_lockfile {
+  if [ ! -z "$LOCKFILE" ]; then
+    mkdir -p `dirname $LOCKFILE`
+    if ( set -o noclobber; echo "$$" > "$LOCKFILE" ) &> /dev/null; then
+      trap 'httracker_unset_lockfile' INT TERM EXIT
+    else
+      echo "Could not create lockfile $LOCKFILE, exiting"
+      exit 1
+    fi
+  fi
+}
+
+# Remove lockfile
+function httracker_unset_lockfile {
+  if [ ! -z "$LOCKFILE" ]; then
+    $rm -f $LOCKFILE || echo "Could not remove lockfile $LOCKFILE"
+  fi
+}
+
+# Check lockfile
+function httracker_check_lockfile {
+  local pid process
+
+  if [ ! -z "$LOCKFILE" ] && [ -f "$LOCKFILE" ]; then
+    pid="`cat $LOCKFILE`"
+    process="`ps --no-headers -o comm $pid`"
+    if [ "$?" == "0" ] && [ "`ps --no-headers -o comm $$`" == "$process" ]; then
+      echo "Another program is running for $LOCKFILE, skipping run"
+      exit
+    else
+      echo "Found old lockfile $LOCKFILE, removing it"
+      unset_LOCKFILE
+    fi
+  fi
 }
 
 # Initialize
-httracker_set_env
+httracker_initialize