From: Shashank Date <sdate@...>
Date: 2003-01-30T16:41:08+09:00
Subject: Re: realtime display of stdout while using Kernel::backtick

# Many ways to execute a shell-command

STDOUT.sync = true

cmd = 'ping -n 5 localhost'
#'osql -Usa -Pdbmteam -S EMACHINE -d master -Q"select * from
sysobjects" -n -h-1 -w 1000'
# method 1
open("|#{cmd}") do |f|
    f.each{|line| print line}
end

# method 2
system("#{cmd}")


# method 3
puts `#{cmd}`

# method 4
IO.popen(cmd) do |p|
   p.each do |line|
     puts line
   end
end

"Kevin Moore" <kgm_lists@ameritech.net> wrote in message
news:hQ1_9.398$dL4.323583@newssrv26.news.prodigy.com...
> Hello,
>
> I am using Ruby to develop an automatic build script at my company. We do
> embedded development, and have three code bases that get built and nested
> inside each other. (microcontrollers booting dsps in the box, and a GUI
that
> can update the box's code)
>
> So far the script is working great. If does just what I need, and the
other
> developers are impressed with the flexibility of the language. I have only
> one problem: When I use the backtick operator (actually %x{}) I can
capture
> that stdout output, but I can't display it in real time (as the external
> program prints it)
>
> I am doing something like this:
>
> puts(%x{#{some_compilicated_pvcs_command_string}})
>
> This drives PVCS quite well. It checks out all ( >200) my files and prints
a
> message listing each file that it checks out. Unfortunately, all the text
> spews out at once! When the tool is invoked directly from the command
line,
> the text comes one line at a time, synchronous with the checkouts.
>
> I am running the _very_ impressive Win32 distribution (version 1.6.8-8)
from
> the Pragmatic Programmer site.
>
> Is there a way to set up Ruby to send the output of the tool to the
console
> as it comes in? Any advice would be greatly appreciated!
>
> This is a fantastic language. I can't wait to do more with it!
>
> Kevin M.
>
>