UNIX for Dummies Questions & Answers

Hello

Yes I'm a noob so thanks for your help.

I have a unix exicutable that renders video under os x (unix). As it renders frames it echos (or outputs) information to the terminal about which frame it's up too an how long it took etc. I am looking for a way to pipe this information so I can use it for other purposes. The problem is that when I pipe the information, it waits until all the frames have been rendered and then redirects the total output of information to the next command

Is there a way to pipe the echos to another command as they happen rather than waiting until the entire process has finished?

I've tried various methods of "render | do something else" without success.

Thanks in advance

Andrew

check tee command ...

When running the executable on a terminal without piping/redirecting, the output is line buffered so you see the info by lines. To force the output to be line buffered, either run the command under pty, or preload a share library which calls setbuf/setvbuf. If you have ssh running, do

Code:

ssh -t localhost command args |...

thanks guys, appreciate it. Sorry to ask this but do you mind posting a codded example? Tried did some experiments with tee but just raised more questions :-)

as an experiment, I setup a function that mimicks what my video render is doing and tried to route it too the osx "say" command which just makes the mac speak the variable

Code:

# !/bin/sh

shoutOut()
{
  echo "Line 1"
  sleep 2
  echo "Line 2"
  sleep 2
  echo "Line 3"
}

shoutOut | tee say

This did not work. Any suggestions?

Thanks guys

Your shoutout function (executed by the shell) actually flushs each line. To simulate the frame rendering program, I will use perl which can be told to do line flushing or not:

Code:

~$ cmd='print scalar localtime;sleep(5);print scalar localtime'
~$ perl -le"$cmd" 
Thu Feb 25 18:16:45 2010
Thu Feb 25 18:16:50 2010
~$ perl -le"$cmd" |while read x;do date "+%T $x";done
18:17:01 Thu Feb 25 18:16:56 2010
18:17:01 Thu Feb 25 18:17:01 2010
~$ perl -le"\$|=1;$cmd" |while read x;do date "+%T $x";done
18:17:05 Thu Feb 25 18:17:05 2010
18:17:10 Thu Feb 25 18:17:10 2010
~$ ssh -t localhost "perl -le'$cmd'" |while read x;do date "+%T $x";done
18:17:21 Thu Feb 25 18:17:21 2010
18:17:26 Thu Feb 25 18:17:26 2010