Bug #2351: system() hardlinked to /bin/sh
http://redmine.ruby-lang.org/issues/show/2351

Author: Marcus Franke
Status: Open, Priority: Normal
Category: core
ruby -v: ruby 1.8.7 (2008-08-11 patchlevel 72) [x86_64-linux]

I encountered this problem while using a feature of the very powerful zsh(ell).

In zsh one can use regular expressions in shell commands, like accessing files in 
different locations with one command:

cat -la /mnt/server(1|2)/some/path/and/file_log

The default /bin/sh does not as it is a bash in most cases.

Example:
 % irb    
 >> ENV['SHELL']
 => "/usr/bin/zsh"
 >> system('cat /mnt/server(1|2|3)/file | sed, awk, etc.')
 sh: Syntax error: "(" unexpected
 => false

I can update the ENV['SHELL'] to every setting I'd like, but system() will always refer to /bin/sh. 

Thus my script will always fail as long as I do not circumvent this feature with something like:

system('/usr/bin/zsh -c "cat /mnt/server(1|2|3)/file | sed, awk, etc."')

I tested this with different ruby versions installed by different Linux distributions:
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux] Ubuntu 9.04
ruby 1.8.7 (2008-08-11 patchlevel 72) [x86_64-linux] openSuSE 11.1
ruby 1.8.7 (2009-04-08 patchlevel 160) [i386-freebsd7]
ruby 1.8.5 (2006-08-25) [i386-linux] CentOS release 5.3 (Final)


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