View source for GNU parallel

'''GNU parallel''' is a shell tool for executing jobs in parallel using one or more computers. A job can be a single command or a small script that has to be run for each of the lines in the input. The typical input is a list of files, a list of hosts, a list of users, a list of URLs, or a list of tables. A job can also be a command that reads from a pipe. GNU parallel can then split the input and pipe it into commands in parallel.

==Usage examples / tutorial==

* Install GNU parallel from the CLI (or, just use your distro's repo):
 $ wget pi.dk/3 -qO - | bash -x

 $ cat foo.fasta
 >RECORD1
 ATGGCTGTCTTCTTGCTTGCCACTTCCACCATAATGTTCCCAACGAAGATAGAAGCAGCA
 GATTGTAATGGTGCATGTTCACCTTTCGAGGTGCCACCGTGCCGCTCAAGTGATTGTCGT
 TGTGTCCCTATAGGACTATTTGTTGGTTTCTGCATACATCCAACTGGACTTTCATCTGTT
 >RECORD2
 GCGAAGATGGTCGACGAACATCCCAACTTATGTCAATCTGATGATGAATGCATGAAGAAA
 GGAAGTGGCAATTTTTGCGCTCGTTACCCTAATAATTATATCGATTATGGATGGTGTTTT
 GACTCTGATTCTGAAGCACTGAAAGGCTTCTTGGCCATGCCTAGGGCAACCACCAAGTAA

 $ cat foo.fasta | parallel --pipe --recstart '>' -N1 cat';' echo =====
 >RECORD1
 ATGGCTGTCTTCTTGCTTGCCACTTCCACCATAATGTTCCCAACGAAGATAGAAGCAGCA
 GATTGTAATGGTGCATGTTCACCTTTCGAGGTGCCACCGTGCCGCTCAAGTGATTGTCGT
 TGTGTCCCTATAGGACTATTTGTTGGTTTCTGCATACATCCAACTGGACTTTCATCTGTT
 =====
 >RECORD2
 GCGAAGATGGTCGACGAACATCCCAACTTATGTCAATCTGATGATGAATGCATGAAGAAA
 GGAAGTGGCAATTTTTGCGCTCGTTACCCTAATAATTATATCGATTATGGATGGTGTTTT
 GACTCTGATTCTGAAGCACTGAAAGGCTTCTTGGCCATGCCTAGGGCAACCACCAAGTAA
 =====

 $ printf '=%.0s' {1..79}
 $ printf %79s | tr " " "="
 $ seq -s= 79 | tr -d '[:digit:]'
 $ perl -E 'say "=" x 79'
 $ head -c 79 < /dev/zero | tr '\0' '='

 $ cat /usr/share/dict/words | parallel --pipe --blocksize 500k wc

 $ seq 1 10 |shuf | parallel --pipe --files -N 3 sort -n | parallel -mj1 sort -nm
 $ rm -f /tmp/*.par
 $ seq 1 10 |shuf | parallel --pipe --files -N 3 sort -n | parallel -mj1 sort -nm {} ";"rm {}

==External links==
*[http://www.gnu.org/software/parallel/ Official website]
*[http://www.gnu.org/software/parallel/parallel_tutorial.html GNU parallel tutorial] (same as running: <code>`man parallel_tutorial`</code>)
*[http://pi.dk/1/ GNU Parallel videos] on YouTube

[[Category:Linux Command Line Tools]]