Krab

Krab is a collection of shell functions that I find useful.

Usage

$ ./bin/krab -h
Usage: $ krab [OPTION] [COMMAND]

COMMAND is one of:
    - envsubst
    - migrate
    - run
    - semver-components
    - semver-validate
    - stdio-alert
    - stdio-confirm
    - stdio-inform
    - stdio-state
    - time

OPTION is one or more of the following:
    -h  Show this message.

Requirements

• Bash

Features & use cases

Notifications

Formatted notifications can be sent to stderr using the stdio-* commands. To display an error, run krab stdio-alert 'Something went wrong!'.

Templating

krab envsubst substitutes environment variables in its stdin using a syntax familiar from web templating engines, avoiding the dollar sign ($) in shell variable notation, which is often a special character. To make your shell greet you, run echo 'Hi there, {{ USER }}!' | ./bin/krab envsubst.

Test runner

If your tests are all executable files in a ./tests directory, you can run them using find ./tests -print0 | xargs -0 ./bin/krab run -l. Say ./tests contains other files such as test asserts as well, and you want to run your tests in order, you can prefix them with a number, and add an extension like 01-linter.test and run find ./tests -type f -name '*.test' -print0 | sort -z | xargs -0 krab run -l.

Timing & benchmarks

To time or benchmark the execution of a command, use time -i X, where X is the number of iterations you want the command to be run. The output is similar to the UNIX time command, but all times are averaged across the iterations. Example:

$ ./bin/krab time -i 3 sleep 3
Average run times across 3 iteration(s):
Real: 3.000 seconds
User: 0.000 seconds
Sys: 0.000 seconds

Development

Requirements

• ShellCheck
• Git

Building

Run ./bin/build-dev.

Testing

Run ./bin/test.

Releasing a new version

Run ./bin/release $VERSION where $VERSION is a valid Semantic Version.