From: Xin Wang <redmine@...>
Date: 2010-05-20T14:06:22+09:00
Subject: [ruby-core:30320] [Bug #3321] Kernel#system do not execute command in subshell even if it contains variable assignments

Bug #3321: Kernel#system do not execute command in subshell even if it contains variable assignments
http://redmine.ruby-lang.org/issues/show/3321

Author: Xin Wang
Status: Open, Priority: Normal
Category: core
ruby -v: ruby 1.9.1p378 (2010-01-10 revision 26273) [i686-linux]

When there are variable assignments in command, Kernel#system in Ruby v1.9 execute it using bare fork&exec instead subshell. It cause command execution failed silently.

So '=' must also be a special character to be recognized as a sign to execute command in subshell.


For example:

$ cat ./script.sh
#!/bin/sh

echo $TEST



$ irb
irb(main):001:0> system('TEST=test ./script.sh')
=> nil
irb(main):002:0> system('TEST=test ./script.sh 2>/dev/null')
test
=> true
irb(main):003:0> ~


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