Recursively replace files in the current directory and subdirectories using regular expressions

rsub

# Usage
# (Note: This command does not handle spaces in filenames!)
# * cd into the directory containing the files and subdirectories of files in
#   which you wish to carry out string substitution using a regex
# * Run the command:
#   rsub 'search regex' 'replacement text'
# * This will effect the desired substitution in files in the current directory
#   and in any subdirectories

# Explaination
# * The -I {} allows you to grab each thing that xargs iterates over
#   as {}
# * So {} is probably the most important thing
# 
egrep -rl "$1" .|xargs -I {} sed -i "s/$1/$2/g" {}