A collection of shell (sh/bash/zsh) utilities. Just playing around with this, nothing serious here.

It's pretty POSIX-compliant. The only exception is the use of mktemp which is needed to run the test-suite.

Otherwise, it's a pretty straightforward file you could import. Comes with some basic features for writing tests of complicated methods, and a couple examples.

This was strongly inspired by Aditya Athalye's Shell ain't a bad place to FP series.

I used a couple of these patterns at work, so I thought it would be nice to make a separate version publicly, for easy copy-paste.

Haven't been using this style very long, so I wouldn't say I'm endorsing it yet, or really understanding it yet fully.

. utils.sh

$ echo "one
two
three
" | map "tr -s 'a-z' 'A-Z'" \
    | filter 'test "4" = "$(tee | wc -m)"' \
    | count
2

map/filter/for_each are all taking predicate functions that are applied to each line. They don't have to be inline commands like that. If you were capitalizing things a lot, it would work equally well so long as the function takes its input through STDIN and returns its output on STDOUT.

$ capitalize() {
    tr -s 'a-z' 'A-Z'
}

$ echo "abc\ndef\n" | map capitalize