Check comand status in ruby

[Arthur Korneyew]

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 !

 

[ts]

A> 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