Asp Forum - Re: getting stdout and stderr for system calls on windows

Vassilis Rizopoulos

12/8/2005 9:59:00 PM

I ended up with the following after this discussion. It doesn't separate
stderr and stdout, but for what I want it, it's more than enough. And I
added crude benchmarking as well:) :
There was also an exitcode method in there (you can get the exitcde from
@process).

#Executes a command on a dos shell, redirecting stderr to stdout ("2>&1")
#
#You can then access the output and the return value for the command.
#
#This is meant as a last-resort replacement for popen3 (because of
problems with VC++6.0 and the Ruby One-Click Installer).
#
#_exec_time_ provides the Time spent running the command.
class ExecCmd
attr_reader :output,:cmd,:exec_time
#When a block is given, the command runs before yielding
def initialize cmd
@output=""
@exec_time=0
@cmd=cmd
@cmd_run=cmd+" 2>&1" unless cmd=~/2>&1/
if block_given?
run
yield self
end
end

#Runs the command
def run
t1=Time.now
IO.popen(@cmd_run){|f|
@output=f.read
@process=Process.waitpid2(f.pid)[1]
}
@exec_time=Time.now-t1
end
#Returns false if the command hasn't been executed yet
def run?
return false unless @process
return true
end
#Returns true if the command was succesfull.
#
#Will return false if the command hasn't been executed
def success?
return @process.success? if @process
return false
end
end

www-data wrote:
> I have the same problem, and i'm likely going to end up using this
> syntax inside a system call:
>
> (((dmake target | tee stdout.txt) 3>&1 1>&2 2>&3 | tee stderr.txt) 3>&1
> 1>&2 2>&3) 2>&1 | tee output.txt
>
> where output.txt will contain stderr + stdout
> stdout.txt will contain stdout
> stderr.txt will contain stderr
>
> There is a description of how this works here:
> http://www.cpqlinux.com/red...
> Scroll down to "Capturing stderr with tee Swapping stderr and stdout"
> Ugly as hell but it does the trick... hopefully someone knows a cleaner
> way to do this within ruby?
>
> --
>
> ara.t.howard wrote:
>
>>On Thu, 24 Nov 2005, Damphyr wrote:
>>
>>
>>>system 'echo blabla'
>>>stdout.
>>>
>>>Cheers,
>>>V.-
>>
>>i was working on this at one point:
>>
>> harp:~ > cat a.rb
>> class Redirector
>> require "tempfile"
>> attr_accessor "ruby"
>> def initialize
>> @ruby = "ruby"
>> @script = tempfile
>> @script.write <<-ruby
>> stdout, stderr = ARGV.shift, ARGV.shift
>> File::unlink out rescue nil
>> File::unlink err rescue nil
>> STDOUT.reopen(open(stdout,"w"))
>> STDERR.reopen(open(stderr,"w"))
>> system(ARGV.join(' '))
>> ruby
>> @script.close
>> end
>> def run command, redirects = {}
>> stdout = redirects.values_at("stdout", :stdout, "o", :o,
>>1).compact.first
>> tout = nil
>> unless stdout
>> tout = tempfile
>> stdout = tout.path
>> end
>> stderr = redirects.values_at("stderr", :stderr, "e", :e,
>>2).compact.first
>> terr = nil
>> unless stderr
>> terr = tempfile
>> stderr = terr.path
>> end
>> system "#{ @ruby } #{ @script.path } #{ stdout } #{ stderr } #{
>>command }"
>> ret = IO::read(stdout), IO::read(stderr), $?.exitstatus
>> tout.close! if tout
>> terr.close! if terr
>> ret
>> end
>> def tempfile
>> Tempfile::new(Process::pid.to_s << rand.to_s)
>> end
>> end
>>
>> redirector = Redirector::new
>>
>> stdout, stderr, exitstatus = redirector.run "echo 42"
>> p [stdout, stderr, exitstatus]
>>
>> redirector.run "echo 42", 1 => "out", 2 => "err"
>> p [IO::read("out"), IO::read("err")]
>>
>>
>> harp:~ > ruby a.rb
>> ["42\n", "", 0]
>> ["42\n", ""]
>>
>>regards.
>>
>>-a
>
>
>

--
http://www.braveworl...

____________________________________________________________________
http://www.f... - äùñåÜí õðçñåóßá çëåêôñïíéêïý ôá÷õäñïìåßïõ.
http://www.f... - free email service for the Greek-speaking.

comp.lang.ruby

Re: getting stdout and stderr for system calls on windows

Vassilis Rizopoulos

x Login to ForumsZone