Restore lessc -w functionality, extendable to anything that needs to watch a file.

The latest version of the less compiler in ruby has reduced the functionality of watching a file, so we wrote this little script (which we put in ~/bin/lessc-w) to restore the old functionality :

#!/bin/bash

LESSFILE=$1
CSSFILE=`basename $1 .less`.css

if [ "$2" != "-f" ]; then
    if [ "`file -b $LESSFILE`" != "ASCII text" ]; then
        echo "file $1 doesn't look like a less file...., looks like a `file -b $LESSFILE`";
        echo "usage: lessc-w lessfile.less [-f]";
        exit
    fi
fi

while true; do
    inotifywait -e modify $LESSFILE && \
    echo "Rebuilding styles" && \
    lessc $LESSFILE > $CSSFILE
done

As you can see it’s very simple to tweak this to any program that needs to be run when a file is changed.