A collection of my hand-crafted bash scripts and helper functions for various common tasks.
bin/
is a collection of finished scripts, for doing everything you need to do related to a specific task (e.g.dns
can both set and fetch DNS values from a variety of providers)lib/
is a collection of adapters to interact with 3rd party tools or scripts, e.g. cloudflare/letsencrypt/etcutil/
is a collection of pure bash functions to make development in bash easier e.g. logging/configuration/error handling/etc.
For a list of my favorite CLI utilities for Linux/macOS, and much more, see here:
https://docs.sweeting.me/s/system-monitoring-tools ⭐️
For my Fish shell functions, snippets, and reading list see here:
https://github.com/pirate/fish-functions
- https://linux.die.net/man/
- https://wiki.tilde.fun/admin/linux/cli/start
- https://explainshell.com/ (Github)
- https://tldr.sh/
- http://bropages.org/
- https://regex101.com/
- ShellCheck: life-changing BASH linter and testing toolkit https://github.com/koalaman/shellcheck
- How to do things safely in bash https://github.com/anordal/shellharden/blob/master/how_to_do_things_safely_in_bash.md
- 30 interesting commands for the Linux shell – Víctor López Ferrando https://www.lopezferrando.com/30-interesting-shell-commands/
- 7 Surprising Bash Variables https://zwischenzugs.com/2019/05/11/seven-surprising-bash-variables/
- anordal/shellharden https://github.com/anordal/shellharden/blob/master/how_to_do_things_safely_in_bash.md
- barryclark/bashstrap https://github.com/barryclark/bashstrap
- BashPitfalls : Greg's Wiki http://mywiki.wooledge.org/BashPitfalls
- Common shell script mistakes http://www.pixelbeat.org/programming/shell_script_mistakes.html
- Comparison of all the UNIX shells http://hyperpolyglot.org/unix-shells
- Defensive Bash Programming https://www.kfirlavi.com/blog/2012/11/14/defensive-bash-programming/index.html or https://jonlabelle.com/snippets/view/markdown/defensive-bash-programming
- Bash FAQ and Cookbook https://mywiki.wooledge.org/BashFAQ
- Detecting the use of "curl | bash" server side https://idontplaydarts.com/2016/04/detecting-curl-pipe-bash-server-side
- Gensokyo Blog - Use Bash Builtins shell,fish,bash https://blog.gensokyo.io/a/fafbe742.html
- Rich’s sh (POSIX shell) tricks http://www.etalabs.net/sh_tricks.html
- Shell Scripts Matter https://dev.to/thiht/shell-scripts-matter
- Shell Style Guide https://google.github.io/styleguide/shell.xml
- Shellcode Injection - Dhaval Kapil https://dhavalkapil.com/blogs/Shellcode-Injection/
- Something you didn't know about functions in bash http://catonmat.net/blog/bash-functions
- Ten More Things I Wish I’d Known About bash https://zwischenzugs.com/2018/01/21/ten-more-things-i-wish-id-known-about-bash
- Ten Things I Wish I’d Known About bash https://zwischenzugs.com/2018/01/06/ten-things-i-wish-id-known-about-bash
- Testing Bash scripts with BATS https://opensource.com/article/19/2/testing-bash-bats
- Testing Bash scripts with Critic.sh https://github.com/Checksum/critic.sh
- Useful BASH and UNIX commands https://cb.vu/unixtoolbox.xhtml
- When Bash Scripts Bite :: Jane Street Tech Blogs https://blogs.janestreet.com/when-bash-scripts-bite/
- Bashible: Ansible-like framework for bash-based devops https://github.com/mig1984/bashible
- Auto-parse help text from comment at the top of script https://samizdat.dev/help-message-for-shell-scripts/
- Make bash scripts safer by writing them in Rust https://github.com/rust-shell-script/rust_cmd_lib
- Additional shell options for non-trivial bash scripts https://saveriomiroddi.github.io/Additional-shell-options-for-non-trivial-bash-shell-scripts/
- Bash unit testing framework https://github.com/pgrange/bash_unit
- What exactly was the point of
[ “x$var” = “xval” ]
? https://www.vidarholen.net/contents/blog/?p=1035 - How to Write Indempotent Bash Scripts https://arslan.io/2019/07/03/how-to-write-idempotent-bash-scripts/
- Better Bash Scripting in 15 Minutes http://robertmuth.blogspot.com/2012/08/better-bash-scripting-in-15-minutes.html
- Argbash: Argument parsing toolkit https://github.com/matejak/argbash
- Bash Exit Traps: Towards Safer Bash Scripts http://redsymbol.net/articles/bash-exit-traps/
- Advanced Bash Scripting Guide by Mendel Cooper https://hangar118.sdf.org/p/bash-scripting-guide/
- Bash Debugging Zine by Julia Evans https://wizardzines.com/comics/bash-debugging/
- The Art of Command Line https://github.com/jlevy/the-art-of-command-line
If any of these links are down, see https://archive.sweeting.me or https://archive.org for mirrors.
#!/usr/bin/env bash
### Bash Environment Setup
# http://redsymbol.net/articles/unofficial-bash-strict-mode/
# https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
# set -o xtrace
# set -x
# shopt -s nullglob
set -o errexit
set -o errtrace
set -o nounset
set -o pipefail
IFS=$'\n'
SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
timeout executes the ssh command (with args) and sends a SIGTERM if ssh doesn't return after 5 second. for more details about timeout, read this document: http://man7.org/linux/man-pages/man1/timeout.1.html
timeout 5 some-slow-command
# or on mac:
brew install coreutils
gtimeout 5 some-slow-command
# parse and handle passed CLI arguments sanely
while getopts ":mnopq:rs" Option
do
case $Option in
m ) echo "Scenario #1: option -m- [OPTIND=${OPTIND}]";;
n | o ) echo "Scenario #2: option -$Option- [OPTIND=${OPTIND}]";;
p ) echo "Scenario #3: option -p- [OPTIND=${OPTIND}]";;
q ) echo "Scenario #4: option -q-\
with argument \"$OPTARG\" [OPTIND=${OPTIND}]";;
# Note that option 'q' must have an associated argument,
#+ otherwise it falls through to the default.
r | s ) echo "Scenario #5: option -$Option-";;
* ) echo "Unimplemented option chosen.";; # Default.
esac
done
#!/bin/bash
scratch=$(mktemp -d -t tmp.XXXXXXXXXX)
function finish {
rm -rf "$scratch"
}
trap finish EXIT
# kill any processes matching given regex
pkill nginx
a='$b'
b='$c'
c=d
echo $a # $b
# First level.
eval echo $a # $c
# Second level.
eval eval echo $a # d
# Third level.
# This shell builtin replaces the current process with a specified command
# useful for when the last command in a script is a long running process you want to kick off, and you dont want it to be a child of bash
exec some-daemon-that-runs-forever
check pkg info of any installed package, and compare semver/date/incremental versions easily
Have total control over piping between processes, including doing crazy things like piping a processes own stdout into its stdin, launching complex directed graphs of pipes as a single process, etc.