tldr/pages/common/parallel.md

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# parallel
> Run commands on multiple CPU cores.
- Gzip several files at once, using all cores:
`parallel gzip ::: {{file1}} {{file2}} {{file3}}`
- Read arguments from stdin, run 4 jobs at once:
`ls *.txt | parallel -j4 gzip`
- Convert JPG images to PNG using replacement strings:
`parallel convert {} {.}.png ::: *.jpg`
- Parallel xargs, cram as many args as possible onto one command:
`{{args}} | parallel -X {{command}}`
- Break stdin into ~1M blocks, feed each block to stdin of new command:
`cat {{big_file.txt}} | parallel --pipe --block 1M {{command}}`
- Run on multiple machines via SSH:
`parallel -S {{machine1}},{{machine2}} {{command}} ::: {{arg1}} {{arg2}}`