What is a shell script?

Wiki.

Best practices

• Best Practices for Writing Bash Scripts (kvz.io).
• Use the Unofficial Bash Strict Mode (Unless You Looove Debugging (redsymbol.net)
• kvz/bash3boilerplate

# Define error reporting level, file seperator, and init direcotry.
function init(){
    set -Eeuo pipefail; # set -o xtrace;
    IFS=$'\n\t'
    DIR=$PWD;
    ROOT_DIR="$(dirname "${DIR}")";
}
init

Avoid exit when child process fails

Comment out the set -Eeuo pipefail.

Error params

• 4.3.1 The Set Builtin (gnu.org/software/bash)

Execute in terminal

• Create a launcher.
• Set working directory and command.
• Check 'Open in terminal'.

Where to look for a serious working example?

• epety/100-shell-script-examples.
• natelandau/shell-scripts.
• Netbeans 8.2 installer. It is a ~ 120 MB large shell script. You can download it here. It contains functions, ifs, loops and so on.

Great reads

• man bash.
• Advanced Bash-Scripting Guide from The Linux Documentation Project.
• Say what? Kipibenkipod view of the world.
• Naming_Conventions.
• Defensive BASH Programming.

Useful tools

• nbshell plugin for Netbeans.
• isao/shell - various scripts and support files for noodling on the command line, esp bbedit, git, etc
• xbot/shell - This repo hosts miscellaneous scripts I use in my daily life.
• smilejay/shell - some of Jay's shared Shell codes. http://smilejay.com
• hjxhjh/shell - some of my shared shell scripts
• Crabbit/shell - My shell scripts.
• geekcomputers/Shell - Some of the handy shell scripts I have created/acquired
• dl - fetch remote file for convenient local reading

Good to know

• Remember to add backslash '' for special symbols in texts. Example, echo "I don't want it." will raise error don't: command not found and the output will become I want it.. Noticed this when pushing a commit and some of the text was missing because I used `` to highlight a code.
• Shell scripts are very strict about spaces so if[[ ... ]] won't work because after if there should be a space.

Debugging

• http://redsymbol.net/articles/unofficial-bash-strict-mode/

• https://www.shellcheck.net/

• set -x for debug. More in learn-basics/debug.sh.

• use exit to stop the script.

• Better write outpout to file with echo -e, otherwise the output in terminal can be misleading.

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Started in Jan 2018