Tags » shell scripting

TIL: Comparing two files in a bash script

Inspect the exit value of cmp --silent.

TIL: Use rm -v to see which files are being removed

Whose code am I running in GitHub Actions?

I wanted to know what third-party code I was using in my GitHub Actions. I was able to use standard text processing tools and shell pipelines to get a quick tally.

TIL: Debugging some confusing behaviour with find and xargs

Use the --verbose flag to see what xargs is doing; don’t rely on find to return files in a consistent order.

TIL: Use $_ to get the last argument to the previous bash command

This allows you to write commands like mkdir myfolder && cd $_ or git init myrepo && cd $_.

TIL: The open command can ask questions

If you pass an argument that can’t be easily identified as a file or a URL, open will ask you what to do next. This may be a surprise if you were trying to use it in a script.

TIL: Use the -n/-i flags to avoid overwriting files with cp and mv

TIL: Using errexit and arithmetic expressions in bash

TIL: Add the -v flag to see what rm is deleting

TIL: Create a directory before you cp or mv a file to it

Making the fish shell more forgetful

A few commands that help me keep unwanted entries out of my shell’s autocomplete.

Starting Docker just before I need it

I don’t keep Docker running all the time, but intercepting the docker command means it’s always running when I need it.

Checking lots of URLs with curl

A bash script to check the HTTP status code of a bunch of URLs, for simple and portable uptime checking.

How to do parallel downloads with youtube-dl

Finding the latest screenshot in macOS Mojave

TIL: How to use xargs for parallel processing

A shell alias for tallying data

A way to count records on the command-line.

Safely deleting a file called ‘-rf *’

If for some reason you create a file called -rf *, it’s possible to delete it safely. But really, don’t create it in the first place.

Pretty printing JSON and XML in the shell

Quick shell access for Docker containers

A Bash function for quickly getting shell access to Docker containers.

Useful Bash features: exit traps