Surviving bash

The flagship product of modern unix is certainly better than any other 80s shell

August 10, 2018 — October 18, 2018

computers are awful
macos
POSIX

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General, not macOS-specific or Linux-specific, and see also shells to yak-shave your way into whole other shell paradigms. Or fish for a less awful user experience.

I just don’t care enough to remember. This makes me a Bad Hacker.

1 Command line tips

See command lines which are mostly bash specific because everything is hard in bash.

2 bash history

3 Vars, expansions, filenames, whitespace hell

3.1 Tilde expansion

Tilde expansion is complicated. Best to avoid tildes and use ${HOME}.

3.2 files extension munging in bash

for file in *.html;
    mv "$file" "`basename $file .html`.txt";
done

or:

mv "$file" "${file%.html}.txt"

Don’t forget the quotes, or it will explode when you have spaces in your filenames and delete stuff that you loved. (bash has hurt me so often; why have I not abandoned it?.)

4 For loops

Watch out for horrible problems with handling of delimiters. Anyway, for loops are not insane.

#!/bin/bash

for i in $( ls ); do
    echo item: $i
done

5 Init file madness

Weird bash syntax errors about ‘end of file’.