An opinionated set of thumb rules that Shrikant Sharat Kandula follows after a decade of writing shell scripts. His starter template looks nice as well:

#!/usr/bin/env bash

set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace
fi

if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then
    echo 'Usage: ./script.sh arg-one arg-two

This is an awesome bash script to make your life better.

'
    exit
fi

cd "$(dirname "$0")"

main() {
    echo do awesome stuff
}

main "$@"

Simon Willison figured out how to run a SQL query directly against a CSV file using the sqlite3 CLI:

sqlite3 :memory: -cmd '.mode csv' -cmd '.import taxi.csv taxi' \
  'SELECT passenger_count, COUNT(*), AVG(total_amount) FROM taxi GROUP BY passenger_count'

Ie TL;DR’d the one-liner for ya, but you’ll have to go to Simon’s site for the explainer.

Bonnie I-Man Ng:

I was working on bioinformatics a few years ago and was amazed by those single-word bash commands which are much faster than my dull scripts, time saved through learning command-line shortcuts and scripting.

Recent years I am working on cloud computing and I keep recording those useful commands here. Not all of them is oneliner, but I put effort on making them brief and swift. I am mainly using Ubuntu, Amazon Linux, RedHat, Linux Mint, Mac and CentOS, sorry if the commands don’t work on your system.

So Argc is a little Rust program that your bash scripts can use to make handling command-line parameters easy. You describe the options, parameters, and subcommands in comments like this:

# @describe A demo cli

# @cmd Upload a file
# @arg target!                      File to upload
upload() {
    echo "cmd                       upload"
    echo "arg:  target              $argc_target"
}

Then you trust Argc to parse that and do the heavy lifting:

eval "$(argc -e $0 "$@")"

The only drawback (aside from potential parsing bugs) to this approach is your script now depends on having argc in the machine’s executable path. i.e. – it’s not portable.

What’d be even cooler, IMHO, would be to instead use argc as a pre-processor of sorts that spits out a pure-bash implementation from your input script. Regardless, a cool idea!

Read the comments for all the bug reports and iteration. 🔥

Martin Tournoij lays out a bunch of ways he finds zsh more compelling than bash.

There are many more things. I’m not going to list them all here. None of this is new; much (if not all?) of this has around for 20 years, if not longer. I don’t know why bash is the de-facto default, or why people spend time on complex solutions to work around bash problems when zsh solves them. I guess because Linux used a lot of GNU stuff and bash was came with it, and GNU stuff was (and is) using bash. Not a very good reason, certainly not one 30 years later.

Any git repository may contain tons of information about commits, contributors, and files. Extracting this information is not always trivial, mostly because there are a gadzillion options to a gadzillion git commands – I don’t think there is a single person alive who knows them all. Probably not even Linus Torvalds himself :).

A handy shell script to help you undo all the things (commits, pushes, pulls, you name it).

tmpsms is a command line utility written in POSIX sh that allows you to get a temporary phone number and receive SMSes. It uses Upmasked temporary SMS service in order to receive the messages. This is a very useful tool for those who use are testing applications during bug bounty hunting or just need some privacy and don’t wan’t to use your personal phone number.

I don’t know when I’d ever use this, but I love that it’s POSIX compliant and depends on just a few other CLI tools (curl, jq, and fzf).

Themeable and has a game-inspired menu system 🔥

critic.sh exposes high level functions for testing consistent with other frameworks and a set of built in assertions. One of my most important goals was to be able to pass in any shell expression to the _test and _assert methods, so that one is not limited to the built-ins.

The coverage reporting is currently rudimentary, but it does indicate which lines haven’t been covered. It works by running the tests with extended debugging, redirecting the trace output to a log file, and then parsing it to determine which functions/lines have been executed. It can definitely be improved!

See a demo of critic.sh in action on asciinema 📽️

Jeffrey Paul shares a ⛴ load of goodies. I particularly like this idea:

I have a Makefile in my home directory… that I use to store common tasks related to my local machine… The one I use most often, though, is make clean, which takes everything in ~/Desktop and moves it into ~/Documents/$YYYYMM (creating the month directory in the process if it doesn’t exist), and also empties trashes.

Reader beware: 4154 words, approximately a 23 minute read

When people see me use these shortcuts, they often ask me, “What did you do there!?” There’s minimal effort or intelligence required, but to really learn them, I recommend using one each day for a week, then moving to the next one. It’s worth taking your time to get them under your fingers, as the time you save will be significant in the long run.

Good advice on how to adopt these. Habit formation requires persistence.

it comes with convenient features such as autocomplete suggestion and gesture typing keyboard. It is useful for quickly troubleshooting server problems on the go, or in your bed in the middle of the night. If you occassionally use the SSH app on your phone, you may want to give Swell.sh a try!

I bet you can learn a lot about Bash scripting from this project. Comes with a caps locked disclaimer:

DO NOT USE THIS IN ANY PUBLIC FACING SERVER. THIS IS NOT SECURE. FOR EDUCATIONAL USE ONLY.

Learn from Ryan Palo about the super-powers of the “short-circuit” policy in Bash.

In Bash, the && and || (AND and OR) operators work via a “short-circuit” policy.

if [[ "$1" -gt 5 ]] && [[ "$1" -lt 10 ]]; then

This checks the first condition. If the first condition is true, then there’s a possibility the whole thing could be true, so it checks the second condition. If the second condition is true, then the whole thing is true! However, if the first condition is false, then there’s no reason to check the second condition, because the whole thing could never possibly be true with the first one false.

Generates a slick looking bar chart of command usage from your .bash_history to learn and share where you’ve been spending your key-presses on the command line.

This post from Daniel Weibel not only explains how macOS uses an outdated version of Bash, but also how to upgrade to the latest Bash via Homebrew.

One thing that many macOS users don’t know is that they are using a completely outdated version of the Bash shell. However, it is highly recommended to use a newer version of Bash on macOS, because it enables you to use useful new features.

$ bash --version
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin18)
Copyright (C) 2007 Free Software Foundation, Inc.

The reason Apple uses this old version of Bash has to do with licensing. Bash 4.0 and newer uses the GNU General Public License v3 (GPLv3), which Apple doesn’t support. There are some discussions about this on Reddit.

Version 3.2 of GNU Bash is the last version with a license that Apple is willing to accept, and so it sticks with it.

A hypervisor that traps Linux system call and translates them into Darwin’s system calls. It can interpret ELF files so Linux binaries run without any modification.

Quickly peek at a file in the lower 3rd of your tmux session by adding this one line to your .bashrc:

peek() { tmux split-window -p 33 "$EDITOR" "$@" || exit; }

Don’t forget to set $EDITOR first!

The closer your development environment mirrors your production environment, the better. And we’re all using HTTPS in production, right? Right?!

twa is a shell script that audits a given website using nothing but bash, awk, curl, and nc. Throw it in your $PATH and see how your site(s) security stacks up.

(Note: requires Bash 4 which is not packaged with macOS because licensing. You can upgrade Bash via homebrew. Learn more here.)

The aim of Bash Infinity is to maximize readability of bash scripts, minimize the amount of code repeat and create a central repository for a well-written, and a well-tested standard library for bash.

It seems to me that by the time you need something as fancy/full-featured as this, maybe the task at hand has outgrown Bash? Cool, nonetheless. 👍

Saverio Miroddi explains how to write tab-completion scripts in any language, with an example in Ruby, and how to use them in both Bash and Zsh. As is common with well-received blog posts, it even inspired some open source (for making tab completion scripts trivial).

The overall purpose of Neofetch is to be used in screen-shots of your system. Neofetch shows the information other people want to see. There are other tools available for proper system statistic/diagnostics.

Supports almost 150 different operating systems, so odds are it has you covered. Check my results below. Pretty decent uptime for a laptop, no?