The do set operation
Like most of the rvm set operations, do lets your perform commands against all installed rubies. Unlike the others, there is a key distinction - do lets you run any command (versus just ruby / gem and the like) and if it is only run against a single ruby, it performs the equivelent of do (e.g. no error message) after setting up the environment. As an example,
$ rvm do bash -c 'echo $GEM_HOME'
Will iterate over each ruby, calling bash with the given arguments. e.g, showing:
info: default (ree-1.8.7-2010.02): ruby 1.8.7 (2010-04-19 patchlevel 253) [i686-darwin10.4.0], MBARI 0x6770, Ruby Enterprise Edition 2010.02 /Users/sutto/.rvm/gems/ree-1.8.7-2010.02 info: jruby-1.5.1: jruby 1.5.1 (ruby 1.8.7 patchlevel 249) (2010-06-06 f3a3480) (Java HotSpot(TM) 64-Bit Server VM 1.6.0_20) [x86_64-java] /Users/sutto/.rvm/gems/jruby-1.5.1 info: rbx-1.0.1-20100603: rubinius 1.0.1 (1.8.7 release 2010-06-03 JI) [x86_64-apple-darwin10.3.0] /Users/sutto/.rvm/gems/rbx-1.0.1-20100603 info: ree-1.8.7-20090928: ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.3.0], MBARI 0x6770, Ruby Enterprise Edition 20090928 /Users/sutto/.rvm/gems/ree-1.8.7-20090928 info: ree-1.8.7-2010.02: ruby 1.8.7 (2010-04-19 patchlevel 253) [i686-darwin10.4.0], MBARI 0x6770, Ruby Enterprise Edition 2010.02 /Users/sutto/.rvm/gems/ree-1.8.7-2010.02 info: ruby-1.8.7-head: ruby 1.8.7 (2010-07-17 patchlevel 300) [i686-darwin10.4.0] /Users/sutto/.rvm/gems/ruby-1.8.7-headdo info: ruby-1.9.2-head: ruby 1.9.2dev (2010-07-01 revision 28513) [x86_64-darwin10.3.0] /Users/sutto/.rvm/gems/ruby-1.9.2-head info: ruby-1.9.2-preview3: ruby 1.9.2dev (2010-05-31 revision 28117) [x86_64-darwin10.3.0] /Users/sutto/.rvm/gems/ruby-1.9.2-preview3
Alternatively, calling against a single ruby will perform as such:
$ rvm ree do bash -c 'echo $GEM_HOME'
Shows the following, minus the info statements as above:
/Users/sutto/.rvm/gems/ree-1.8.7-2010.02
