Shell script

Aside from 🤮, I need to write Shell script in several place.

This is a note for me.

test

file

• -e: exists
• -f: exists & regular # "regular" means both text and binary. In other words excluding directory, symlink and device
• -d: exists & directory
• -r: exists & the user has read permission
• -w: exists & the user has write permission
• -x: exists & executable
• -N: exists & modified from last read
• -s: exists & non empty

string

• -n: non empty
• -z: empty

set

• -: Enable

• +: Disable

• -e: exit with non 0

• -u: exit with undefined variable

• -x: print executed command

• -o: # TODO

• pipefail: # TODO

assign value and print to tty

> dir="$(mktemp --directory | tee --append /dev/tty)"
/tmp/tmp.y2NaKkqILD
> echo $dir
/tmp/tmp.y2NaKkqILD

How to delegate multiline string to another command

• https://stackoverflow.com/a/28090709
• https://github.com/kachick/dotfiles/pull/1063/files#diff-0f761dec41f629bec1988e89fea47b068a4274580b5e4d80baeb47d45007cc54R7
• https://github.com/kachick/dotfiles/blob/beabf65a88671770b85029b71450fabee5c9868b/pkgs/git-log-fzf/git-log-fzf.bash#L28

If escape is a hard thing

1. https://github.com/kachick/dotfiles/blob/beabf65a88671770b85029b71450fabee5c9868b/pkgs/fzf-bind-posix-shell-history-to-git-commit-message/fzf-bind-posix-shell-history-to-git-commit-message.bash#L9
2. https://github.com/kachick/dotfiles/blob/beabf65a88671770b85029b71450fabee5c9868b/pkgs/safe_quote_backtik/safe_quote_backtik.bash#L1-L3