3 ms·

This is one of the reasons shell languages feel kind of functional. But they're not really designed like a functional language so they feel kind of clunky. On

This is one of the reasons shell languages feel kind of functional. But they're not really designed like a functional language so they feel kind of clunky. On the subject of "oh, I could do that if..." I know exactly how you feel. I really want the ability to pass multiple filestreams to a command, so you could, say, use cat on the outputs of two commands. Assuming the syntax was @`<pipeline>`, It would like something like this: foo|grep bar|cat @`baz|grep bar`|sort -rn|tail The above script assumes that the commands foo and baz are generating lines with time signatures at the start, and then checking for the most recent entries. I chose the @` syntax for its similarity to the lisp @, syntax, but it could be anything. Unfortunately, I think the only way to do this would be to monkey-patch either open(2) or fopen(2), probably both, which would be a Really Bad Idea (tm).

dllthomas 11y ago
I'm not exactly sure what semantics you intend, it seems like you might be able to spell this { foo; baz; } | grep bar | sort -rn | tail or, in bash only: cat <(foo | grep bar) <(baz | grep bar) | sort -rn | tail This is assuming you didn't intend interleaving, for which the second syntax would work but you'd need something other than cat.
- qwertyuiop924 11y ago
  the <(...) syntax seems to be what I was looking for, passing a stream/pipeline to a function where a filename was expected. Hey, you learn something every day. EDIT: Unless you're just piping both of them to STDIN. piping two files to STDIN is useful, just not as useful as the thing that I wanted. This seems to be what you're doing.
  - dllthomas 11y ago
    It sets up a fifo, and passes in one end of it by name: $ echo <(:) <(:) /dev/fd/63 /dev/fd/62 So yeah, should be what you want for that use case :) As I mentioned though, it's a bashism.
    - qwertyuiop924 11y ago
      Now I'm going to have to build a portable version of that. It shouldn't be too hard.

dllthomas 11y ago

I'm not exactly sure what semantics you intend, it seems like you might be able to spell this { foo; baz; } | grep bar | sort -rn | tail or, in bash only: cat <(foo | grep bar) <(baz | grep bar) | sort -rn | tail This is assuming you didn't intend interleaving, for which the second syntax would work but you'd need something other than cat.

qwertyuiop924 11y ago
the <(...) syntax seems to be what I was looking for, passing a stream/pipeline to a function where a filename was expected. Hey, you learn something every day. EDIT: Unless you're just piping both of them to STDIN. piping two files to STDIN is useful, just not as useful as the thing that I wanted. This seems to be what you're doing.
- dllthomas 11y ago
  It sets up a fifo, and passes in one end of it by name: $ echo <(:) <(:) /dev/fd/63 /dev/fd/62 So yeah, should be what you want for that use case :) As I mentioned though, it's a bashism.
  - qwertyuiop924 11y ago
    Now I'm going to have to build a portable version of that. It shouldn't be too hard.