Perl Guru Forums: Perl Programming Help: Frequently Asked Questions: How do I do a tail -f in perl?

CGI/Perl Guide | Learning Center | Forums | Advertise | Login

Site Search: in


	MAIN INDEX	SEARCH POSTS	WHO'S ONLINE	LOG IN

Home: Perl Programming Help: Frequently Asked Questions:
How do I do a tail -f in perl?

Jasmine
Administrator

Jan 26, 2001, 10:38 AM

Post #1 of 1 (3938 views)

How do I do a tail -f in perl?	Can't Post

(From the Perl FAQ)

How do I do a tail -f in perl?

First try

Code

    seek(GWFILE, 0, 1);

The statement seek(GWFILE, 0, 1) doesn't change the current position, but it does clear the end-of-file condition on the handle, so that the next <GWFILE> makes Perl try again to read something.

If that doesn't work (it relies on features of your stdio implementation), then you need something more like this:

Code

        for (;;) { 
          for ($curpos = tell(GWFILE); <GWFILE>; $curpos = tell(GWFILE)) { 
            # search for some stuff and put it into files 
          } 
          # sleep for a while 
          seek(GWFILE, $curpos, 0);  # seek to where we had been 
        }

If this still doesn't work, look into the POSIX module. POSIX defines the clearerr() method, which can remove the end of file condition on a filehandle. The method: read until end of file, clearerr(), read some more. Lather, rinse, repeat.

Search for (options)

Web Applications & Managed Hosting Powered by Gossamer Threads
Visit our Mailing List Archives