Who needs pipes?

B <<< $(A)
or: C

By: asg0451
2009-08-30 20:20:18

What Others Think

Wow, that's cool! I liked it!
danpos · 663 weeks ago
Here documents are cool, but I think pipes win the fewest characters race. A|B
bwoodacre · 663 weeks ago
@bwoodacre However the outcomes are slightly different. The "here document" concatenates A's output into a single line, whereas piping leaves A's output untouched.
flatcap · 663 weeks ago
bash specific, useful for construct like: while read line; do var=line; done < $(command) echo "$var" A < <(B)
remil · 663 weeks ago
sry, should be ... done < <(command) also useful construct diff <(cmd1) <(cmd2)
remil · 663 weeks ago
@flatcap you are right! I keep forgetting that here documents turn a file into *arguments* for the command not standard input. Makes sense since there shouldn't be two ways to do the same thing.
bwoodacre · 662 weeks and 6 days ago
Sorry, what I just said is wrong. :-( http://www.gnu.org/software/bash/manual/bashref.html#Redirections
bwoodacre · 662 weeks and 6 days ago
I can think of at least one occasion where this will be useful: I SSH into a server from a phone that doesn't have the pipe character.
flipouk · 662 weeks and 6 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: