gitwatch/gitwatch.sh

#!/usr/bin/env bash
#
# gitwatch - watch file or directory and git commit all changes as they happen
#
# Copyright (C) 2012  Patrick Lehner
#   with modifications and contributions by:
#   - Matthew McGowan
#   - Dominik D. Geyer
#
#############################################################################
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#############################################################################
#
#   Idea and original code taken from http://stackoverflow.com/a/965274 
#       (but heavily modified by now)
#
#   Requires the command 'inotifywait' to be available, which is part of
#   the inotify-tools (See https://github.com/rvoicilas/inotify-tools ),
#   and (obviously) git
#

REMOTE=""
BRANCH="master"
SLEEP_TIME=2
DATE_FMT="+%Y-%m-%d %H:%M:%S"

shelp () { # Print a message about how to use this script
    echo "gitwatch - watch file or directory and git commit all changes as they happen"
    echo ""
    echo "Usage:"
    echo "${0##*/} [-s <secs>] [-d <fmt>] [-r <remote> [-b <branch>]] <target>"
    echo ""
    echo "Where <target> is the file or folder which should be watched. The target needs"
    echo "to be in a Git repository; or in the case of a folder, it may also be the top"
    echo "folder of the repo."
    echo ""
    echo " -s <secs>        after detecting a change to the watched file or directory,"
    echo "                  wait <secs> seconds until committing, to allow for more"
    echo "                  write actions of the same batch to finish; default is 2sec"
    echo " -d <fmt>         the format string used for the timestamp in the commit"
    echo "                  message; see 'man date' for details; default is "
    echo "                  '+%Y-%m-%d %H:%M:%S'"
    echo " -r <remote>      if defined, a 'git push' to the given <remote> is done after"
    echo "                  every commit"
    echo " -b <branch>      defines the branch which should be pushed automatically; if"
    echo "                  not given, the branch argument to 'git push' is omitted and"
    echo "                  a default push is done (see git man pages for details); if"
    echo "                  given, push is run like 'git push <remote> <branch>; if no"
    echo "                  remote was define with -r, this option has no effect"
}

while getopts b:d:hp:r:s: option # Process command line options 
do 
    case "${option}" in 
        b) BRANCH=${OPTARG};;
        d) DATE_FMT=${OPTARG};;
        h) shelp; exit;;
        p|r) REMOTE=${OPTARG};;
        s) SLEEP_TIME=${OPTARG};;
    esac
done

shift $((OPTIND-1)) # Shift the input arguments, so that the input file (last arg) is $1 in the code below

if [ $# -ne 1 ]; then # If no command line arguments are left (that's bad: no target was passed)
    shelp # print usage help
    exit # and exit
fi


is_command () { # Tests for the availability of a command
	which $1 &>/dev/null
}

# Check dependencies and die if not met
for cmd in git inotifywait; do
	is_command $cmd || { echo "Error: Required command '$cmd' not found." >&2; exit 1; }
done
unset cmd


# These two strings are used to construct the commit comment
#   They're glued together like "<CCPREPEND>(<DATE&TIME>)<CCAPPEND>"
# If you don't want to add text before and/or after the date/time, simply
#   set them to empty strings
CCPREPEND="Scripted auto-commit on change "
CCAPPEND=" by gitwatch.sh"

IN=$(readlink -f "$1")

if [ -d $1 ]; then
    TARGETDIR=$(sed -e "s/\/*$//" <<<"$IN") # dir to CD into before using git commands: trim trailing slash, if any
    INCOMMAND="inotifywait --exclude=\"^${TARGETDIR}/.git\" -qqr -e close_write,move,delete,create $TARGETDIR" # construct inotifywait-commandline
    GITADD="." # add "." (CWD) recursively to index
    GITINCOMMAND="-a" # add -a switch to "commit" call just to be sure
elif [ -f $1 ]; then
    TARGETDIR=$(dirname "$IN") # dir to CD into before using git commands: extract from file name
    INCOMMAND="inotifywait -qq -e close_write,move,delete $IN" # construct inotifywait-commandline
    GITADD="$IN" # add only the selected file to index
    GITINCOMMAND="" # no need to add anything more to "commit" call
else
    echo >&2 "Error: The target is neither a regular file nor a directory."
    exit 1
fi

while true; do
    $INCOMMAND # wait for changes
    sleep $SLEEP_TIME # wait some more seconds to give apps time to write out all changes
    DATE=$(date "$DATE_FMT") # construct date-time string
    cd $TARGETDIR # CD into right dir
    git add $GITADD # add file(s) to index
    git commit $GITINCOMMAND -m"${CCPREPEND}(${DATE})${CCAPPEND}" # construct commit message and commit

    if [ -n "$REMOTE" ]; then # are we pushing to a remote?
       if [ -z "$BRANCH" ]; then # Do we have a branch set to push to ?
           git push $REMOTE # Branch not set, push to remote without a branch
       else
           git push $REMOTE $BRANCH # Branch set, push to the remote with the given branch
       fi
    fi
done