Maintains a textile of sorted unique lines.

add.sh

#!/usr/bin/env bash

# MIT Licensed
# Maintainer: Volkan Özçelik <me@volkan.io>

# A quick and dirty way to keep a sorted text file of things.
# 
# Usage:
#
#     ./add 'lorem ipsum' 'dolor' 'dolor' 'dolor' 'ipsum dolamet' 'john doe'
#
# And when you `cat ./lines.txt` you'll get:
#
#     dolor
#     ipsum dolamet
#     john doe
#     lorem ipsum
#
# That is, there won’t be any duplicate lines on the files, and the file 
# will be sorted at all times as long as you use this script.
#
# Not rocket surgery, but it’s scratching a certain itch of mine nonetheless :)
#
# Suggestions to make it better are welcome.

# Create the file if it does not exist:
touch lines.txt

# These are temporary buffers:
touch .tmp
touch .tmps

echo -n "" > .tmp

# Copy all arguments to the first buffer, 
# taking care of the arguments that have spaces in them too:
for i in `seq 1 $#`
do
    eval a=\$$i
    echo "${a}" >> .tmp
done

# Copy what we already have, sort and dedupe:
cat lines.txt >> .tmp
cat .tmp | sort -u > .tmp2

# Backup the current file, just in case:
TS=`date +%s`
cp lines.txt lines.txt."${TS}"

# Replace the newly sorted data into `lines.txt`:
rm lines.txt
mv .tmp2 lines.txt