Environment variables

ruby-talk
1

Hi,

How can I set environment variables to a program that I run using
Kernel#system?

Thanks,
Maurício

2

  How can I set environment variables to a program that I run using
Kernel#system?

With ENV

pigeon% cat b.rb
#!/usr/bin/ruby
ENV['AA'] = "bb"
system('a.sh')
pigeon%

pigeon% cat a.sh
#!/bin/sh
echo $AA
pigeon%

pigeon% b.rb
bb
pigeon%

Guy Decoux

3

How can I set environment variables to a program that I run using
Kernel#system?
Hi Mauricio,

If you use Unix/Linux I think the normal ENV
should do the job.

Under Windows it’s more tricky.

I collected these snipplets that appeared
on that list some time ago.

code by Hee-Sob Park - posted here:

http://ruby-talk.com/10006

def system(command)
Win32API.new(“crtdll”, “system”, [‘P’], ‘L’).Call(command)
end

code by Hee-Sob Park - posted here:

http://ruby-talk.com/10006

def `(command)
popen = Win32API.new(“crtdll”, “_popen”, [‘P’,‘P’], ‘L’)
pclose = Win32API.new(“crtdll”, “_pclose”, [‘L’], ‘L’)
fread = Win32API.new(“crtdll”, “fread”, [‘P’,‘L’,‘L’,‘L’], ‘L’)
feof = Win32API.new(“crtdll”, “feof”, [‘L’], ‘L’)
saved_stdout = $stdout.clone
psBuffer = " " * 128
rBuffer = “”
f = popen.Call(command,“r”)
while feof.Call( f )==0
l = fread.Call( psBuffer,1,128,f )
rBuffer += psBuffer[0…l]
end
pclose.Call f
$stdout.reopen(saved_stdout)
rBuffer
end

4

I tested on the version of ruby I have in windows (1.72) and the ENV
way worked. However, the code you show seems pretty interesting!

Thanks,
Maurício

Armin Roehrl wrote:

···

(…)
Under Windows it’s more tricky.

I collected these snipplets that appeared
on that list some time ago.
(…)