Build a Simple TODO List with Shell Script 🐚

#shell #bash #linux #todolist

Managing tasks directly from the terminal can be a breeze with the power of shell scripting! In this post, I'll walk you through creating a simple yet functional TODO list using a few shell functions. We'll store tasks in a text file, add unique identifiers to each item, and provide commands for adding, removing, and clearing tasks.

Let’s dive in! 🚀

Prerequisites ⚙️

You'll need a terminal using bash or zsh. The following functions can be added to your ~/.zshrc or ~/.bashrc file to make them available as commands in your terminal.

Step 1: Set Up Your Storage 🎲

First, let’s create an environment variable that defines where your tasks will be stored. Add this line to your configuration file:

export TODO="${HOME}/todo.txt"

This will store your task list in a file called todo.txt located in your home directory.

Step 2: Define Your Functions ✨

Now let's add some shell functions to manage our TODO list:

tla() { [ $# -eq 0 ] && cat $TODO || (echo "$(echo $* | md5sum | cut -c 1-4) 👉🏼 $*" >> $TODO && cat $TODO) ;}
tlr() { sed -i '' "/^$*/d" $TODO && cat $TODO ;}
tl() { cat $TODO ;}
tlc() { cat /dev/null > $TODO ;}

Here’s what each function does:

tla (Todo List Add): Adds tasks to the list. It generates a 4-character md5 hash to serve as a unique identifier for each task. If no argument is passed, it displays the current task list.
tlr (Todo List Remove): Removes tasks from the list by matching their md5 identifier.
tl (Todo List): Simply displays the current list.
tlc (Todo List Clear): Clears the entire task list, removing all entries at once.

At the end of each operation, the current state of your TODO list will be displayed.

Step 3: See It in Action ☕️

Here’s a quick demonstration of how these commands work:

➜  ~ tl       
➜  ~ tla test 0
# 0e57 👉🏼 test 0
➜  ~ tla test 1
# 0e57 👉🏼 test 0
# 2490 👉🏼 test 1
➜  ~ tla test 2
# 0e57 👉🏼 test 0
# 2490 👉🏼 test 1
# b0b3 👉🏼 test 2
➜  ~ tlr 2490
# 0e57 👉🏼 test 0
# b0b3 👉🏼 test 2
➜  ~ tl
# 0e57 👉🏼 test 0
# b0b3 👉🏼 test 2
➜  ~ tlc
➜  ~ tl

tla test 0: Adds "test 0" to the list with an md5 identifier.
tlr 2490: Removes the task with the identifier 2490 (in this case, "test 1").
tlc: Clears the list.

Conclusion ✍️

With just a few lines of shell script, you now have a functional TODO list right in your terminal. You can easily add, remove, or clear tasks with simple commands. This setup is lightweight and can be modified to fit your workflow.

Feel free to extend these functions or add your own twists. Happy hacking! 🚀

Top comments (17)

Given Ncube • Sep 16

Bash has always been this mystery to me, every time I need a script I would reach for PHP or Ruby

Joe • Sep 17

Bash is pretty easy with one major exception. When your command includes any tokens that bash recognizes, it will attempt to perform several types of expansions to it. It does this iteratively until nothing else will expand.

When you take advantage of this on purpose, it's great, but getting it to leave something the way it was using quoting/escaping can be quite challenging. You have to learn that the hard way - mostly by trial and error. The bash trace flags (-v and -x) help with figuring out how the original text of the script gets expanded.

Also, some people make a variable names uppercase for some reason. I started out that way, but switched to lowercase for everything except environment variables.

Given Ncube • Sep 17

I hear people say bash is great until you need an array

Ernane Ferreira • Sep 17

But who needs them? Bash and arrays have a relationship as smooth as trying to split a string without 'awk'

Given Ncube • Sep 18

Ernane Ferreira • Sep 17

I completely understand you! I often feel the same way. Bash isn’t my main language, but I enjoy challenging myself from time to time. When it's something urgent, of course, I’ll turn to a tool or language I’m more comfortable with. However, whenever possible, it's worth stepping out of your comfort zone and trying something new. Sometimes, in those moments, you might gain insights from a language you're less familiar with, which you can even apply to your primary one. If you have the time — and sometimes the sanity — give it a try!