5 ms·

Should’ve been named zip. Is there an unzip? But of course it can’t be named zip because that’s the compressor, so I’m really asking whether there’s an unpaste

Should’ve been named zip. Is there an unzip? But of course it can’t be named zip because that’s the compressor, so I’m really asking whether there’s an unpaste. I guess the closest is awk {print $1;}, but it makes me wince every time I write it. (I already know that would give syntax errors as written here.)

vimax 5y ago
Depending on the data, the right options for xargs would work, and there's the pr command I haven't used much.
- sillysaurusx 5y ago
  Hmm. Does xargs give you a way to skip the first arg? xargs -n 2 I {} almost works, but you’d need a way to extract a specific arg out of the {}. Which I just realized I don’t know how to do. “(at 0 {})” would be a nice construction. But then of course now you’re writing xargs -n 2 -I {} echo (at 1 {}) instead of just awk {print $2}, so it’s mission failed successfully.
  - quicklime 5y ago
    If you're just looking for a single column, then as zamfi mentioned, cut does the job: $ paste <(printf "a\nb\nc\n") <(printf "1\n2\n3\n") | cut -f2 1 2 3 It makes sense that "cut" and "paste" would be inverse operations, but too bad that GUIs repurposed these words for clipboard operations. But awk can do both, and does so in a single pass: $ paste <(printf "a\nb\nc\n") <(printf "1\n2\n3\n") | awk '{ print $1 > "letters"; print $2 > "numbers" }' $ cat letters a b c $ cat numbers 1 2 3
    - sillysaurusx 5y ago
      What! I didn’t know awk could do that within single quotes. The heck, it implements a subset of sh? Thanks!
      - camhutch 5y ago
        awk has some basic redirection features. gawk documentation: https://web.mit.edu/gnu/doc/html/gawk_6.html#SEC41 https://web.mit.edu/gnu/doc/html/gawk_6.html#SEC41 posix documentation: https://pubs.opengroup.org/onlinepubs/009695299/utilities/awk.html#tag_04_06_13_10 https://pubs.opengroup.org/onlinepubs/009695299/utilities/aw...
    - stewartbutler 5y ago
      Kinda-sorta related, you can pipe to a multivariable loop: paste <(printf "a\nb\nc\n") <(printf "1\n2\n3\n") | while read x y; do echo "$y -- $x"; done Kinda silly for this example, but very useful in things like `kubectl` pipelines -- you can do something like this: kubectl get pods --all-namespaces | awk '{print $1 " " $2}' | grep "doesntexist" | while read x y; do kubectl delete pod $y --namespace $x --wait=false; done This lets you list all pods in a cluster, grep a selection of them by name, and delete them in a batch, regardless of which namespace they are in, while shuffling the order of args into different flags.
      - sillysaurusx 5y ago
        Most useful comment I’ve read in months, for me. Cheers!
      - forty 5y ago
        Sorry, but my shellcheck OCD forces me to say "read without -r will mangle backslashes." ;)
    - CornCobs 5y ago
      TIL you can pipe into files in awk. I've never come across this feature somehow. Is it commonly used?
zamfi 5y ago
if you know the separator, you can use `cut` -- not an unzip per se (doesn't give you the full separated lists, without calling it multiple times anyway) but approximately equal to the awk line
teraflop 5y ago
Now you've got me curious which came first, "paste" or "zip". Python's zip function was added in PEP 201 [1], which credits the Haskell 98 report with the name. The same function appears in all prior versions of the Haskell language that I could find, dating back to Haskell 1.0 in 1990. On the other hand, the GNU coreutils version of paste[2] has copyright dates going all the way back to 1984, which presumably means it was derived from UNIX System V or an even earlier version. [1]: https://www.python.org/dev/peps/pep-0201/ https://www.python.org/dev/peps/pep-0201/ [2]: https://github.com/coreutils/coreutils/blob/master/src/paste.c https://github.com/coreutils/coreutils/blob/master/src/paste...
- nicoburns 5y ago
  It's possible a lisp of some sort predated the Haskell version
- LukeShu 5y ago
  The FreeBSD man page for `paste` claims it first appeared in Unix 32V (1979; derived from v7 Unix, and ancestral to both 4BSD and SysV).
  - mprovost 5y ago
    Here's the commit from 1978: https://github.com/dspinellis/unix-history-repo/blob/Bell-32V-Snapshot-Development/usr/src/cmd/paste.c https://github.com/dspinellis/unix-history-repo/blob/Bell-32... The comments refer to an "old 127 paste command" but I have no idea what that is.
    - LukeShu 5y ago
      I hadn't pursued it further than seeing that it was added in an 1978 commit. Looking at it further, there are a few answers at https://minnie.tuhs.org/pipermail/tuhs/2020-January/019955.html https://minnie.tuhs.org/pipermail/tuhs/2020-January/019955.h... > GWRL stands for Gottfried W. R. Luderer, the author of cut(1) and paste(1), probably around 1978. Those came either from PWB or USG I can verify that neither cut nor past were in PWB 1: https://minnie.tuhs.org/cgi-bin/utree.pl?file=PWB1 https://minnie.tuhs.org/cgi-bin/utree.pl?file=PWB1 > Also "127" was the internal department number for the Computer Science Research group at Bell Labs where UNIX originated
fragmede 5y ago
alias awk1="awk {print $1;}" Counting to 9, inclusive, is left as an exercise for the reader.
- boring_twenties 5y ago
  awp () { local a a=() while [[ -z ${1:#-*} ]] do a=($a $1) shift done local n n=$1 shift awk $a '{print $'$n'}' $* }
- sillysaurusx 5y ago
  Amusingly, I apparently added these to scrap https://github.com/shawwn/scrap https://github.com/shawwn/scrap many years ago. I named them 1st, 2nd, 3rd, and 4th. So I guess I never needed to count to 5, but I'm still two ahead of Valve. https://www.youtube.com/watch?v=jpw2ebhTSKs https://www.youtube.com/watch?v=jpw2ebhTSKs EDIT: Actually, I'd never committed 4th. It was just sitting here in my local scrap. So I guess I counted to three, realized at some later date I needed four, copied 3rd to 4th, then never committed. Oh. Apparently I also have 'nth', which was exactly what I wanted: > echo a b c d | nth 0 3 a d The solution I came up with at the time: #!/bin/bash c="" for n in "$@" do n=$((n+1)) args="${args}${c}\$$n" c=', ' done awk "{ print ${args}; }" Nowadays I'd write it like: awk "{ print $(echo "$@" | args math '1+{}' | replace '^' '$' | trim | joinlines ', '); }" But I admit both are equally cryptic, and the former might even be more readable.
cerved 5y ago
> Is there an unzip? xargs printf

vimax 5y ago

Depending on the data, the right options for xargs would work, and there's the pr command I haven't used much.

sillysaurusx 5y ago
Hmm. Does xargs give you a way to skip the first arg? xargs -n 2 I {} almost works, but you’d need a way to extract a specific arg out of the {}. Which I just realized I don’t know how to do. “(at 0 {})” would be a nice construction. But then of course now you’re writing xargs -n 2 -I {} echo (at 1 {}) instead of just awk {print $2}, so it’s mission failed successfully.
- quicklime 5y ago
  If you're just looking for a single column, then as zamfi mentioned, cut does the job: $ paste <(printf "a\nb\nc\n") <(printf "1\n2\n3\n") | cut -f2 1 2 3 It makes sense that "cut" and "paste" would be inverse operations, but too bad that GUIs repurposed these words for clipboard operations. But awk can do both, and does so in a single pass: $ paste <(printf "a\nb\nc\n") <(printf "1\n2\n3\n") | awk '{ print $1 > "letters"; print $2 > "numbers" }' $ cat letters a b c $ cat numbers 1 2 3
  - sillysaurusx 5y ago
    What! I didn’t know awk could do that within single quotes. The heck, it implements a subset of sh? Thanks!
    - camhutch 5y ago
      awk has some basic redirection features. gawk documentation: https://web.mit.edu/gnu/doc/html/gawk_6.html#SEC41 https://web.mit.edu/gnu/doc/html/gawk_6.html#SEC41 posix documentation: https://pubs.opengroup.org/onlinepubs/009695299/utilities/awk.html#tag_04_06_13_10 https://pubs.opengroup.org/onlinepubs/009695299/utilities/aw...
  - stewartbutler 5y ago
    Kinda-sorta related, you can pipe to a multivariable loop: paste <(printf "a\nb\nc\n") <(printf "1\n2\n3\n") | while read x y; do echo "$y -- $x"; done Kinda silly for this example, but very useful in things like `kubectl` pipelines -- you can do something like this: kubectl get pods --all-namespaces | awk '{print $1 " " $2}' | grep "doesntexist" | while read x y; do kubectl delete pod $y --namespace $x --wait=false; done This lets you list all pods in a cluster, grep a selection of them by name, and delete them in a batch, regardless of which namespace they are in, while shuffling the order of args into different flags.
    - sillysaurusx 5y ago
      Most useful comment I’ve read in months, for me. Cheers!
    - forty 5y ago
      Sorry, but my shellcheck OCD forces me to say "read without -r will mangle backslashes." ;)
  - CornCobs 5y ago
    TIL you can pipe into files in awk. I've never come across this feature somehow. Is it commonly used?

zamfi 5y ago

if you know the separator, you can use `cut` -- not an unzip per se (doesn't give you the full separated lists, without calling it multiple times anyway) but approximately equal to the awk line

teraflop 5y ago

Now you've got me curious which came first, "paste" or "zip". Python's zip function was added in PEP 201 [1], which credits the Haskell 98 report with the name. The same function appears in all prior versions of the Haskell language that I could find, dating back to Haskell 1.0 in 1990. On the other hand, the GNU coreutils version of paste[2] has copyright dates going all the way back to 1984, which presumably means it was derived from UNIX System V or an even earlier version. [1]: https://www.python.org/dev/peps/pep-0201/ https://www.python.org/dev/peps/pep-0201/ [2]: https://github.com/coreutils/coreutils/blob/master/src/paste.c https://github.com/coreutils/coreutils/blob/master/src/paste...

nicoburns 5y ago
It's possible a lisp of some sort predated the Haskell version
LukeShu 5y ago
The FreeBSD man page for `paste` claims it first appeared in Unix 32V (1979; derived from v7 Unix, and ancestral to both 4BSD and SysV).
- mprovost 5y ago
  Here's the commit from 1978: https://github.com/dspinellis/unix-history-repo/blob/Bell-32V-Snapshot-Development/usr/src/cmd/paste.c https://github.com/dspinellis/unix-history-repo/blob/Bell-32... The comments refer to an "old 127 paste command" but I have no idea what that is.
  - LukeShu 5y ago
    I hadn't pursued it further than seeing that it was added in an 1978 commit. Looking at it further, there are a few answers at https://minnie.tuhs.org/pipermail/tuhs/2020-January/019955.html https://minnie.tuhs.org/pipermail/tuhs/2020-January/019955.h... > GWRL stands for Gottfried W. R. Luderer, the author of cut(1) and paste(1), probably around 1978. Those came either from PWB or USG I can verify that neither cut nor past were in PWB 1: https://minnie.tuhs.org/cgi-bin/utree.pl?file=PWB1 https://minnie.tuhs.org/cgi-bin/utree.pl?file=PWB1 > Also "127" was the internal department number for the Computer Science Research group at Bell Labs where UNIX originated

fragmede 5y ago

alias awk1="awk {print $1;}" Counting to 9, inclusive, is left as an exercise for the reader.

boring_twenties 5y ago
awp () { local a a=() while [[ -z ${1:#-*} ]] do a=($a $1) shift done local n n=$1 shift awk $a '{print $'$n'}' $* }
sillysaurusx 5y ago
Amusingly, I apparently added these to scrap https://github.com/shawwn/scrap https://github.com/shawwn/scrap many years ago. I named them 1st, 2nd, 3rd, and 4th. So I guess I never needed to count to 5, but I'm still two ahead of Valve. https://www.youtube.com/watch?v=jpw2ebhTSKs https://www.youtube.com/watch?v=jpw2ebhTSKs EDIT: Actually, I'd never committed 4th. It was just sitting here in my local scrap. So I guess I counted to three, realized at some later date I needed four, copied 3rd to 4th, then never committed. Oh. Apparently I also have 'nth', which was exactly what I wanted: > echo a b c d | nth 0 3 a d The solution I came up with at the time: #!/bin/bash c="" for n in "$@" do n=$((n+1)) args="${args}${c}\$$n" c=', ' done awk "{ print ${args}; }" Nowadays I'd write it like: awk "{ print $(echo "$@" | args math '1+{}' | replace '^' '$' | trim | joinlines ', '); }" But I admit both are equally cryptic, and the former might even be more readable.

cerved 5y ago

> Is there an unzip? xargs printf