diff --git a/functions b/functions
index f996ba8..87586eb 100644
--- a/functions
+++ b/functions
@@ -155,6 +155,22 @@
 }
 
 
+# Prints line number and "message" in warning format
+# warn $LINENO "message"
+function warn() {
+    local exitcode=$?
+    errXTRACE=$(set +o | grep xtrace)
+    set +o xtrace
+    local msg="[WARNING] ${BASH_SOURCE[2]}:$1 $2"
+    echo $msg 1>&2;
+    if [[ -n ${SCREEN_LOGDIR} ]]; then
+        echo $msg >> "${SCREEN_LOGDIR}/error.log"
+    fi
+    $errXTRACE
+    return $exitcode
+}
+
+
 # HTTP and HTTPS proxy servers are supported via the usual environment variables [1]
 # ``http_proxy``, ``https_proxy`` and ``no_proxy``. They can be set in
 # ``localrc`` or on the command line if necessary::