Check comand status in ruby

ruby-talk
1

Hello,

How can I check comand status in Ruby ?
In perl I'm usually using something like that:

$cmd="mv $srcdir/$file $dstdir/$dstfile > /dev/null 2>&1";
$result=system($cmd);
$status=$result >> 8;
if ($status eq '0') {
  &Logit("Ok");
}
else {
  &Logit("Not Ok");
  &Logit("$!");
}

I have tried this code in Ruby but it does not working
as I wish:

IO.popen("/usr/bin/cd /tmp") { |process|
  result = process.gets
  if (result == nil)
    logToScreen "Ok"
  else
    logToScreen "Not Ok"
  end
}

Many thanx !

2

How can I check comand status in Ruby ?

You have the class Process::Status

uln% ri Process::Status
------------------------------------------------- Class: Process::Status
     +Process::Status+ encapsulates the information on the status of a
     running or terminated system process. The built-in variable +$?+ is
     either +nil+ or a +Process::Status+ object.

        fork { exit 99 } #=> 26557
        Process.wait #=> 26557
        $?.class #=> Process::Status
        $?.to_i #=> 25344
        $? >> 8 #=> 99
        $?.stopped? #=> false
        $?.exited? #=> true
        $?.exitstatus #=> 99

     Posix systems record information on processes using a 16-bit
     integer. The lower bits record the process status (stopped, exited,
     signaled) and the upper bits possibly contain additional
     information (for example the program's return code in the case of
     exited processes). Pre Ruby 1.8, these bits were exposed directly
     to the Ruby program. Ruby now encapsulates these in a
     +Process::Status+ object. To maximize compatibility, however, these
     objects retain a bit-oriented interface. In the descriptions that
     follow, when we talk about the integer value of _stat_, we're
     referring to this 16 bit value.

···

------------------------------------------------------------------------

Instance methods:
-----------------
     &, ==, >>, coredump?, exited?, exitstatus, inspect, pid, signaled?,
     stopped?, stopsig, success?, termsig, to_i, to_int, to_s
uln%

Guy Decoux