Pure Bash Bible

Re:Pure Bash Bible by kamaal on Thursday September 19, 2019 @03:40AM (#21014168)

That's not as easy as

    cat something | grep "this" | cut -f 1 | sed -e 's/.../.../'

You end up writing too much code, it's very verbose. Some times symbols are what you want. In fact the biggest progress in the growth of Math happened when they tossed out doing math with words and bought in symbols.

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Re:Pure Bash Bible by masklinn on Thursday September 19, 2019 @03:54AM (#21014229)

> That's not as easy as

> cat something | grep "this" | cut -f 1 | sed -e 's/.../.../'

Literally none of this is actually useful if you're already in Python:

    (
        line.split('\t')[0].replace(…, …)
        for line in open('something')
        if 'this' in line
    )

> You end up writing too much code

I can believe that if you're calling to external processes to perform operations which are pretty much trivial in the language.

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Re:Pure Bash Bible by kamaal on Thursday September 19, 2019 @11:14AM (#21016957)

Of course, if you plan to use one $language alone, you can do anything in that $language.

This question is specific to pipes.

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Re:Pure Bash Bible by masklinn on Thursday September 19, 2019 @12:56PM (#21018096)

> Of course, if you plan to use one $language alone, you can do anything in that $language.

That's missing what I'm noting though, which is that you don't need pipes anywhere near a shell script if you can simply do more of your work in-language. Case in point being that the entire pipeline you cited as an issue has no reason to exist outside of a shell or shell script.

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Re:Pure Bash Bible by kamaal on Friday September 20, 2019 @12:23AM (#21023315)

That's because regexes are an another pain in Python, You have to write a lot of boiler plate exception handling code. Plus the same boiler plate code for file operations.

It doesn't feel like the language was designed for these tasks.

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Re:Pure Bash Bible by Too on Saturday September 21, 2019 @01:51PM (#21036801)

You forgot setting -e and -o pipefail. In case "something" is missing or can't be read for some other reason, your script will just continue happily without warning.

But oh, if you do set -o pipefail the grep will stop the whole pipeline when none of the lines matches "this". So you have to keep fiddling with ${PIPESTATUS[0]}. And none of pipefail or PIPESTATUS are really portable.

Not so simple after all.

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