onchange.sh

#!/bin/bash
#
# Watch current directory (recursively) for file changes, and execute a command
# when a file or directory is created, modified or deleted.
#
# Modified from the original by: Senko Rasic <senko.rasic@dobarkod.hr>
# https://gist.github.com/senko/1154509
#
# Requires:
#     bash
#     fswatch (https://github.com/alandipert/fswatch)
#
# To avoid executing the command multiple times when a sequence of events
# happen, the script waits WAIT_TIME seconds after the change - if more changes
# happen, the timeout is extended by a second again.
#
# Installation (at your own risk):
#     chmod a+rx onchange.sh
#     sudo cp onchange.sh /usr/local/bin
#
# Example use - rsync local changes to the remote server:
#
#     onchange.sh rsync -avt . host:/remote/dir
#
# Released to Public Domain. Use it as you like.
#

EXCLUDE="/\.git/"
WAIT_TIME=1

if [ -z "$1" ]; then
    echo "Usage: $0 cmd ..."
    exit -1;
fi

fswatch -e $EXCLUDE -r . | (
    WAITING="";
    while true; do
        LINE="";
        read -t $WAIT_TIME LINE;
        if test -z "$LINE"; then
            if test ! -z "$WAITING"; then
                    echo "CHANGE";
                    WAITING="";
            fi;
        else
            WAITING=1;
        fi;
    done) | (
    while true; do
        read TMP;
        echo \[`date`\] $@
        "$@"
    done
)