Change indentation: spaces to tabs

To convert space indentation in significant number of files, you may use the
following script.

#!/bin/bash - 
#===============================================================================
#          FILE:  fixtab.sh
#         USAGE:  ./fixtab.sh <directory>
#   DESCRIPTION:  Convert expanded tabs into tabs with 4 space width
#       OPTIONS: $1 directory
#        AUTHOR: Ruslan Osmanov 
#       CREATED: 04/08/2011 03:26:00 PM UZT
#===============================================================================
set -o nounset                              # Treat unset variables as an error

DIR=$1

function usage(){
 echo "bash $0 <directory>"
}

[[ ! -d $DIR ]] && usage

# Correct existing modelines I used to include modelines beginning from set
# expandtab, so this worked for me. If you don't use modelines, comment it out 
find $DIR -name *.php -exec \
 sed -i -e 's%# vim: set expandtab:%# vim: set noet:%g' {} \;

# Retab & format source code
find $DIR -name *.php -exec \
 vim -u NONE \
 -c 'set ft=php' \
 -c 'set shiftwidth=4' \
 -c 'set tabstop=4' \
 -c 'set noexpandtab!' \
 -c 'set noet' \
 -c 'retab!' \
 -c 'bufdo! "execute normal gg=G"' \
 -c wq \
 {} \;

For example:

$ bash ./fixtab.sh /srv/www/myproject

I would be glad, if this helped somebody.