Hi, My problem is the program I want to watch the output of doesn't output stream of data. instead, data is presented on the screen and values change constantly, e.g increasing counters. I think it is more like the top program. How do i tell the program to be on logging mode like top?
--- On Mon, 4/13/09, Chas. Owens <chas.ow...@gmail.com> wrote: > From: Chas. Owens <chas.ow...@gmail.com> > Subject: Re: catching outputs of realtime apps (e.g; 'top(8)' > To: daem0n...@yahoo.com > Cc: beginners@perl.org > Date: Monday, April 13, 2009, 2:28 AM > On Sun, Apr 12, 2009 at 14:14, Michael Alipio > <daem0n...@yahoo.com> wrote: > > > > Hi, > > > > I have a program that constantly displays values on > the screen. The program 'ping' for example. > > > > What I'd like to do is watch the output and as > soon as i see some values, i would do something. For > example, as suppose when pinging a host I would constantly > get a reply. however, if I remove the network cable, of my > pc, I would start seeing host unreachable or something. As > soon as I see this message, I would like to do something. > This is how I want to do this (executing the program once > and watching the output). I could probably run ping every > one second and check the output of each execution, however, > that is not how I want to do it. The program I will be > running has to be run only once, like for example the > 'top' program. > > > > Any idea how to accomplish this? > snip > > Programs like ping that output a stream of information are > easy to work with: > > ping wonkden.net | perl -ne 'print "I saw > $_"' > > Perl defaults to a line buffered mode, so if your the > program you want > to watch outputs lines, then you just need a loop watching > stdin (as > above). To use top, you must put it in logging mode > > OS X > > top -l 0 | perl -ne 'print if /firefox/' > > Linux > > top -b | perl -ne 'print if /firefox/' > > > -- > Chas. Owens > wonkden.net > The most important skill a programmer can have is the > ability to read. > > -- > To unsubscribe, e-mail: beginners-unsubscr...@perl.org > For additional commands, e-mail: beginners-h...@perl.org > http://learn.perl.org/ -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
