Qutting command after so many lines of output

OSI

Hi guy's

I'm currently writing a shell script that will run a particular command and print its output to a file.

The only problem is that when I run the command in question it will print out the first 20 lines and then require the user to press RETURN to see the rest.
I am however only interested in the first 20 lines so I was wondering if there was a way to quit the command once someone lines had been output.

Eg.

The script runs the command, reads the first 20 lines then quits the process rather than just sitting there waiting for user input

Any help will be greatly appreciated

Webmonkey

You could pipe it into head and redirect the output into a file?

something like

command | head - 20 > myfile.out - I'm only guessing this, still relatively new to linux unfort.

Edit- Just noticed it probably the command that pauses automatically after 20 lines? - in that cause you will have to kill the process after the redirection. I amn't really sure how it will work to be honest, but worth a try

Cantab.

perl...

Something like...

'stopper.pl'

#!/usr/bin/perl
my $data=<CIN>;
my $n=0;
while($data)
{
   if($data+=m/\n/)
   {
      $n=$n+1;
      if($n>=20)
      {
          print "Finished.\n";
          exit 0;
      }
   }
}

bash> ./myprog > perl stopper.pl

Might be a bit long-winded. I'm sure awk could do it all in one line.

Khannie

Cantab. wrote: »

bash> ./myprog > perl stopper.pl

That should be a | instead of a > or it'll overwrite your perl script.