Re: Modify a line following a target line?

If you can load the entire file into memory, the following will split the file into records:

my @records = split(/^(?=I)/m, $file);
[download]

The just extract the REFDES and modify the PKG_TYPE

my %pkg_lkup (
   ... => ...,
   ... => ...,
   ... => ...,
);

for my $rec (@records) {
   if ( my ($refdes) = $rec =~ /REFDES=(.*)/ ) {
      if (exists($pkg_lkup{$refdes})) {
         $rec =~ s/PKG_TYPE=.*/PKG_TYPE=$pkg_lkup{$refdes}/;
      }
   }
   print($rec);
}
[download]

In Perl 5.10, the substitution can be written more efficiently as

$rec =~ s/PKG_TYPE=\K.*/$pkg_lkup{$refdes}/;
[download]

Comment on Re: Modify a line following a target line? Select or Download Code

Replies are listed 'Best First'.
Re^2: Modify a line following a target line? by djincnj (Initiate) on Jan 06, 2009 at 17:09 UTC
OK I think I understand this all for the most part, I've been working on files on a line by line basis for so long I didn't think I could break it up any other way. But of course something I imagine is pretty simple has got me stuck. How do I get the entire content of a file into $file? I know how to read a file into @file, but I'm at a loss how to read the whole thing into $file to then split it up.	[reply]
Re^3: Modify a line following a target line? by gwadej (Chaplain) on Jan 06, 2009 at 18:18 UTC
The canonical solution is: `my $file = do { local $/; <>; };` [download] But, we're in Perl, so there's more than one way to do it. `$file = join( '', <> );` [download] also works. Of course, you could look at File::Slurp for a CPAN-based solution that's a little more readable. PS. if you have an open filehandle in `$fh`, you would replace `<>` with `<$fh>` in the above, of course. G. Wade	[reply] [d/l] [select]