[ Top posting fixed ]
[EMAIL PROTECTED] wrote:
>
> "John W. Krahn" <[EMAIL PROTECTED]> 05/25/2004 07:49 PM
> >
> > You can either use Perl's "in-place" edit feature or use a second file
> > to write the data to. Using in-place edit would look something like
> > this:
> >
> > #!/usr/local/bin/perl -w
> > use strict;
> > ( $^I, @ARGV ) = ( '', '/usr/local/bin/perld/exports' );
> >
> > s/^(?=E\d{5})/eject\t0,0,0\t\n/ while <>;
>
> ok does this s/^(?=E\d{5})/eject\t0,0,0\t\n/ while <>;
> say...
>
> from the beginning of the line match 0 or 1 E's with any digits then print
> the eject string? I am not following the { 5 }.
> my E string is 6 characters long, so why the 5?
No, what it says is, match at the beginning of the line if it is
followed by 'E' followed by five digits. \d{5} is just short for
\d\d\d\d\d. (?=) is a positive zero-width look-ahead assertion which
means that the expression 'E\d{5}' must match after the line beginning ^
but it does not effect the position of the match so that the replacement
string "eject\t0,0,0\t\n" is inserted at the line beginning.
John
--
use Perl;
program
fulfillment
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