multido provides a simple command line utility for easily running a shell command multiple times in parallel. One of the most useful examples generally works like this:
$ multido "ssh %s uptime" host1 host2 host3 host1: 22:02:28 up 5 days, 2:52, 0 users, load average: 0.05, 0.04, 0.05 host2: 22:02:27 up 5 days, 24 min, 0 users, load average: 0.05, 0.03, 0.05 host3: 22:02:28 up 6 days, 48 min, 0 users, load average: 0.01, 0.02, 0.05
Unlike say, xargs -P, multido will not just give up if there is a problem with one of the commands, instead it will output the STDERR to STDERR with the RC prepended to each line:
$ multido "ls /etc/%s" passwd missing sudoers passwd: /etc/passwd missing: RC1: ls: /etc/missing: No such file or directory sudoers: /etc/sudoers
multido also accepts stdin from a pipe too, making for easy to chain commands:
$ echo -e "host1\nhost2\nhost3" | multido "ssh %s date" host1: Mon Sep 17 22:08:40 UTC 2012 host2: Mon Sep 17 22:08:40 UTC 2012 host3: Mon Sep 17 22:08:40 UTC 2012
If you have a preferred grouping you would like the commands to be executed in there is a syntax to support grouping:
$ multido "echo %s; sleep 1" [ 'b1a' 'b1b' ] [ 'b2' ] [ 'b3a' 'b3b' 'b3c' ] b1a: b1a b1b: b1b b2: b2 b3a: b3a b3b: b3b b3c: b3c
Or if you just want to limit to batches of N at a time there is syntax available to achieve that:
$ N=2; multido -P$N "echo %s; sleep 1" a b c a: a b: b c: c
TODO: Figure out how to actually get changelog content.
Changelog content for this version goes here.