requirements

#!/usr/bin/env bash
# To add two items to the current .gitignore file:
# requirement Django South
#
# To sort and de-dupe the current .gitignore file:
# requirement

args=( $@ )
args_len=${#args[@]}
requirements_file=${args[args_$len-1]}
requirements=${args[@]:0:args_$len-1}

# Append each argument to its own line:
for item in "$requirements"; do
    pip freeze | grep "$item" >> $requirements_file;
done

# Remove duplicates (and sort):
sort -u $requirements_file -o $requirements_file