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CLI text processing with GNU awk

learnbyexample.github.io

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Re: CLI text processing with GNU awk

#51

Post by coliveira »

ajross wrote: post #43
e63f67dd-065b wrote: post #34

Perhaps my old sysadmin hat is showing through, but I don’t quite see what the advantage of awk is over just writing the same thing in perl. I’ve seen my fair share of horrendous shell scripts from junior sysadmins, and every time I think to myself “the text processing portion would be so much cleaner in Perl”.

There aren't any technical advantages, no. Perl's features are a proper superset of awk (by design!). What's happened is that Kids Today (tm) never learned perl. So they're discovering awk as someone new to the idea of stream processing. And awk was a great idea for that, and it represented a genuine innovation worth emulating. In the late 1970's. Then of course perl did emulate and surpass it. But then got forgotten…

Awk is a useful language that you can learn in one afternoon, after reading the man page and a few examples. And then you can spend your whole life using it for several projects. You cannot do that with perl. That's why awk has a longer shelf life than perl.

Re: CLI text processing with GNU awk

#52

Post by coliveira »

qalmakka wrote: post #13

Awk is fine and dandy but, like wity Sed, I think that it's almost always replaceable with Perl which is way nicer to use, and ubiquitous. Every OS (except Windows) I laid my hands on in the last 15 years has had Perl installed in either its default install or pulled in as a dependency almost immediately (a LOT of stuff depends on Perl in any Unix system). This is, unless you are running on an embedded environment, b…

The difference is that learning pearl is an ordeal that will take several weeks at the minimum. Learning awk can be done in one afternoon, after reading a man page and a few examples. And it really works for the tasks it was designed. So I think awk is superior to perl for the purpose it was created.

Re: CLI text processing with GNU awk

#53

Post by ajross »

coliveira wrote: post #50
ajross wrote: post #42

Earlier quoted context omitted.

Sorry, but that's ridiculous. Any general purpose programming language is a vector for bugs and security problems, but come on: you're genuinely trying to say that a kludge of bash+sed+awk is objectively more "secure" than a single perl script to solve the same problem?

In the case of awk, actually yes, it is safer. The reason is that awk is a very limited language. It has only enough functionality to provide text matching and substitution. It is very difficult to use awk to do anything of high security risk, compared to a language like perl.

But awk is never used alone. You don't solve whole problems with awk, you squish it into a script with a bunch of other junk. My point is that you're making an apples-to-oranges comparison. Sure, "awk" isn't the problem, but "bash" is, and bash is undeniably a more error-prone language than perl. You surely agree with that much, right?

And if you disallow "bash" for security reasons, where does that leave "awk" in the category of useful tools? See my point?

Re: CLI text processing with GNU awk

#55

Post by cb321 »

Galanwe wrote: post #54

99.9% of my awk use case is to split a line (a la "cut - d\ - f) while discarding successive spaces. e.g.: $ echo "key: value" | awk '{print $1}' value Open to a simpler replacement :-)

You might consider: https://github.com/c-blake/bu/blob/main/doc/cols.md

That's in Nim, though that may not be much a barrier. (There may also be other tools in bu/ of interest.)

Re: CLI text processing with GNU awk

#56

Post by zeteo »

e63f67dd-065b wrote: post #34

Perhaps my old sysadmin hat is showing through, but I don’t quite see what the advantage of awk is over just writing the same thing in perl. I’ve seen my fair share of horrendous shell scripts from junior sysadmins, and every time I think to myself “the text processing portion would be so much cleaner in Perl”.

If you're in perl all the time that probably makes a lot of sense. For me, awk is one of the few languages that I can safely set aside for months and then I'm back up to speed in 10 minutes. There's just something very intuitive about it, and it somehow fits very naturally with other common command line tools.

Re: CLI text processing with GNU awk

#57

Post by sureglymop »

ajross wrote: post #43
e63f67dd-065b wrote: post #34

Perhaps my old sysadmin hat is showing through, but I don’t quite see what the advantage of awk is over just writing the same thing in perl. I’ve seen my fair share of horrendous shell scripts from junior sysadmins, and every time I think to myself “the text processing portion would be so much cleaner in Perl”.

There aren't any technical advantages, no. Perl's features are a proper superset of awk (by design!). What's happened is that Kids Today (tm) never learned perl. So they're discovering awk as someone new to the idea of stream processing. And awk was a great idea for that, and it represented a genuine innovation worth emulating. In the late 1970's. Then of course perl did emulate and surpass it. But then got forgotten…

Why is that cringe? They genuinely probably came across awk before perl (I know I did, I read "The AWK Programming Language" and then went on to "The C Programming Language"). Having that said, awk is great and it's been the same for decades and available on every system (the same can't really be said about perl).

Re: CLI text processing with GNU awk

#58

Post by llimllib »

Galanwe wrote: post #54

99.9% of my awk use case is to split a line (a la "cut - d\ - f) while discarding successive spaces. e.g.: $ echo "key: value" | awk '{print $1}' value Open to a simpler replacement :-)

You can do it with cut too:

    $ echo "key:     value" | cut -wf 2
    value
but whether it's actually "simpler" is open to debate

edit: actually gnu cut lacks -w, so this is bsd-only. lol computers, stick with awk

Re: CLI text processing with GNU awk

#59

Post by BaseballPhysics »

zeteo wrote: post #56
e63f67dd-065b wrote: post #34

Perhaps my old sysadmin hat is showing through, but I don’t quite see what the advantage of awk is over just writing the same thing in perl. I’ve seen my fair share of horrendous shell scripts from junior sysadmins, and every time I think to myself “the text processing portion would be so much cleaner in Perl”.

If you're in perl all the time that probably makes a lot of sense. For me, awk is one of the few languages that I can safely set aside for months and then I'm back up to speed in 10 minutes. There's just something very intuitive about it, and it somehow fits very naturally with other common command line tools.

Weird, I feel the same way about Perl.

Re: CLI text processing with GNU awk

#60

Post by cb321 »

llimllib wrote: post #58
Galanwe wrote: post #54

99.9% of my awk use case is to split a line (a la "cut - d\ - f) while discarding successive spaces. e.g.: $ echo "key: value" | awk '{print $1}' value Open to a simpler replacement :-)

You can do it with cut too: $ echo "key: value" | cut -wf 2 value but whether it's actually "simpler" is open to debate edit: actually gnu cut lacks -w, so this is bsd-only. lol computers, stick with awk

Only with FreeBSD `cut`.. coreutils `cut` (Linux) is missing -w as is at least OpenBSD?

EDIT: I see you discovered this. lol computers indeed. ;-)

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