Loading ...
Sorry, an error occurred while loading the content.

Re: [PBML] Look ahead in a file?

Expand Messages
  • daymobrew@yahoo.com
    ... http://www.cpan.org/ ... course. ... know. ] Another option could be to read the entire file into memory, if it s not too big. open( FH, filename.ext );
    Message 1 of 3 , Feb 4, 2004
    • 0 Attachment
      --- In perl-beginner@yahoogroups.com, Jeff 'japhy' Pinyan <japhy@p...>
      wrote:
      > On Feb 3, Electron One said:
      >
      > >Is there a way to look ahead in a file?
      >
      > Well, you can store your current location
      >
      > $here_i_am = tell FILE;
      >
      > do some stuff
      >
      > while (<FILE>) { ... }
      >
      > and then restore your position:
      >
      > seek FILE, $here_i_am, 0;
      >
      > I suggest reading 'perldoc -f seek' and 'perldoc -f tell' for more.
      >
      > --
      > Jeff "japhy" Pinyan japhy@p... http://www.pobox.com/~japhy/
      > RPI Acacia brother #734 http://www.perlmonks.org/
      http://www.cpan.org/
      > <stu> what does y/// stand for? <tenderpuss> why, yansliterate of
      course.
      > [ I'm looking for programming work. If you like my work, let me
      know. ]

      Another option could be to read the entire file into memory, if it's
      not too big.

      open( FH, "filename.ext" ); # Omit 'die' for readability.
      my @Wholefile = <FH>;
      close( FH );

      Now each line is in a different entry of @Wholefile i.e. $Wholefile[0]
      is the first line of the file and $Wholefile[$#Wholefile] is the last
      line.
      This makes it easy to look ahead.
      You can make changes to @Wholefile and then write it back to disk when
      you are finished.
    Your message has been successfully submitted and would be delivered to recipients shortly.