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/etc
• util/ 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/
• Bash Process Backgrounding and Daemon Management https://mywiki.wooledge.org/ProcessManagement
• The Art of Command Line https://github.com/jlevy/the-art-of-command-line
• Basn $Namerefs https://rednafi.com/misc/bash_namerefs/
• Bash Here Strings <<< https://www.gnu.org/software/bash/manual/bash.html#Here-Strings

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

https://news.ycombinator.com/item?id=44096395 more lore around timeout

until curl --silent --fail-with-body 10.0.0.1:8080/health; do	sleep 1 done

https://heitorpb.github.io/bla/timeout/

# 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.

https://github.com/flonatel/pipexec

echo '0.0.0.0:443->443/tcp' | perl -pE 's/0.0.0.0:(\d+)->.*/$1/gm' # 443

# Example: Truncate if longer than 15 characters echo "short string" | sed 's/\(.\{15\}\).*/\1.../' # short string echo "some long string" | sed 's/\(.\{15\}\).*/\1.../' # some long st... # Bonus: get terminal width in columns TERMINAL_WIDTH=$(tput cols)

strace -e trace=clone -e fault=clone:error=EAGAIN

https://medium.com/@manav503/using-strace-to-perform-fault-injection-in-system-calls-fcb859940895