Shell scripting

What's the difference between command and command | cat? There shouldn't be any, right? The first prints the output directly, and the latter prints output via cat, but they should have the same effect. Not so: the latter can cause the command to get stuck indefinitely. This has given a particular CI pipeline of mine quite some headache.

To learn why this happens, and how we can mitigate this problem, we need to dive into the arcane magic that is Unix process management. Join me on this journey.

When needing to perform HTTP calls in shell scripts, Curl is the go-to tool: it's flexible and installed almost everywhere. But Curl is not primarily designed for use in shell scripts. This article explores common caveats when using Curl in shell scripts, and showcases best practices to adhere to.

When you run a command or a script that runs for a long time, it may be helpful to have all its output prefixed with a timestamp. For example we want to change this:

foo
bar
baz

to this:

[2020-12-13 12:20:38] foo
[2020-12-13 12:21:32] bar
[2020-12-13 12:22:20] baz

Here's how you can do it.