para

Parallellizes stdin processing to a number of child processes.

Install

Grab the binary from the relases page.

Examples

Perform line count in four parallell processes.

$ para -children=4 "wc -l" < /usr/share/dict/words
  150230
  152295
  150174
  151689

Perform a massively parallell grep. The -quiet flag suppresses Warning: exit status 1 (child exited with error) for each of the greps that exit without finding the search string.

$ para -children=64 -quiet "grep earde" < /usr/share/dict/words 
bearded
bearder
nonbearded
unbearded

Split a file into eight (the default number of children) pieces. $PARAIDX is set to the child number for each child process. Note though that this is not the same sequential split as split does but a random(-ish) spread of lines into files.

$ para "cat > part.\$PARAIDX" < /usr/share/dict/words ; ls -l part.*
-rw-r--r--+ 1 jb  staff  525350 Mar  1 21:45 part.0
-rw-r--r--+ 1 jb  staff  536848 Mar  1 21:45 part.1
-rw-r--r--+ 1 jb  staff  585446 Mar  1 21:45 part.2
-rw-r--r--+ 1 jb  staff  513315 Mar  1 21:45 part.3
-rw-r--r--+ 1 jb  staff  527953 Mar  1 21:45 part.4
-rw-r--r--+ 1 jb  staff  520258 Mar  1 21:45 part.5
-rw-r--r--+ 1 jb  staff  536501 Mar  1 21:45 part.6
-rw-r--r--+ 1 jb  staff  547481 Mar  1 21:45 part.7