mitch's meanderings» gnu http://mitchcontla.com life, technology, running; links, photos, and videos Tue, 18 Oct 2011 19:32:44 +0000 en hourly 1 http://wordpress.org/?v=3.1.3 Bash: It’s the little things http://mitchcontla.com/2007/06/27/bash-its-the-little-things/ http://mitchcontla.com/2007/06/27/bash-its-the-little-things/#comments Wed, 27 Jun 2007 19:47:50 +0000 mitch http://mitch.contlafamily.com/2007/06/27/bash-its-the-little-things/ The Bash shell always amazes me. I needed to create a Maildir using the typical Maildir/cur, Maildir/new, Maildir/tmp structure and stumbled on this:

$ mkdir -m 0700 -p Maildir/{cur,new,tmp}

The -m and -p options are no-brainers, but the {cur,new,tmp} was new to me. It was easy to figure out what was going to happen… one command to create the Maildir directory, and the three subdirectories, I was simply unfamiliar with the syntax. A quick look at the Bash man page and I discovered Brace Expansion:

Brace expansion is a mechanism by which arbitrary strings may be generated.

A comma separated list between opening and closing braces is expanded by the shell including any preamble (in my case Maildir/) or postscript. Brace expansion can also generate ranges:

$ echo {1..10}
1 2 3 4 5 6 7 8 9 10

Cool, huh?

]]> http://mitchcontla.com/2007/06/27/bash-its-the-little-things/feed/ 2