How to invoke an external program and get anything the pgm returns back

Team,

I have a Ruby script which might invoke an external program.
The external program could be written in: Ruby, Perl, KSH, CSH, BSH,
Etc.
The invoked program might return a value in the the form of a return
code.
For example, a KSH script might execute an exit 99 stmt and which
value I
would like to capture in the invoker, Ruby script.

I tried:
Ruby script segment:
rc = /usr/local/bin/script_name

I also tried in the Ruby caller script:
system("/usr/local/bin/script_name")

KSH:
exit 99

But rc does not have anything of value. It has either true or
false.

Also, using Ruby to Ruby I still can’t get a Ruby script called another
Ruby
script, have the called script returns a value and have the invoker Ruby
script get the value.

Is there anyway to get what I described above?

Thank you

Victor

On Mon, Jul 21, 2008 at 2:35 PM, Victor R. [email protected]
wrote:

Team,

I have a Ruby script which might invoke an external program.
The external program could be written in: Ruby, Perl, KSH, CSH, BSH, Etc.
The invoked program might return a value in the the form of a return code.
For example, a KSH script might execute an exit 99 stmt and which value I
would like to capture in the invoker, Ruby script.

The global variable $? holds the exit status. If you require ‘English’
then you can use the name $CHILD_STATUS instead of $?

KSH:

Thank you

Victor

Jim

On 21.07.2008, at 20:35, Victor R. wrote:

I tried:
Ruby script segment:
rc = /usr/local/bin/script_name

I also tried in the Ruby caller script:
system("/usr/local/bin/script_name")

KSH:
exit 99

Ask $? to get the information.
$?.exitstatus

But rc does not have anything of value. It has either true or
false.

irb> res = ls file_not_exists
ls: file_not_exists: No such file or directory
=> “”
irb> $?.exitstatus
=> 1

According to ri page Kernel.system also sets $?

$ qri Kernel.system
---------------------------------------------------------- Kernel#system
system(cmd [, arg, …]) => true or false

  Executes cmd in a subshell, returning true if the command was
  found and ran successfully, false otherwise. An error status is
  available in $?. The arguments are processed in the same way as
  for Kernel::exec.

hth. regards, Sandor
Sz

On Mon, Jul 21, 2008 at 3:24 PM, Sandor Szücs
[email protected]
wrote:

KSH:
irb> res = ls file_not_exists
system(cmd [, arg, …]) => true or false


Executes cmd in a subshell, returning true if the command was
found and ran successfully, false otherwise. An error status is
available in $?. The arguments are processed in the same way as
for Kernel::exec.

hth. regards, Sandor Szücs

Great! It works!
Here is what I have:

/tmp>cat pg1
#!/usr/local/ruby-1.8.6/bin/ruby -W0
puts “Calling /usr/local/bin/test.rb”
system("/usr/local/bin/test.rb")
puts $?.exitstatus
puts “Calling /usr/local/bin/test.ksh”
system("/usr/local/bin/test.ksh")
puts $?.exitstatus
puts “Now exiting”

/usr/local/bin>cat test.rb
#!/usr/local/ruby-1.8.6/bin/ruby -W0
puts “This is a Ruby script”
exit 199

/usr/local/bin>cat test.ksh
#!/bin/ksh
echo “This is a Korn Shell script”
exit 99

And this is the result:

Calling /usr/local/bin/test.rb
This is a Ruby script
199
Calling /usr/local/bin/test.ksh
This is a Korn Shell script
99
Now exiting

Thank you

Victor

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