If the file is relatively small, why not read it into an array, then just
manipulate the array index? Something like:
my @{lines} = <IN>;
close( IN );
my ${ln} = 0;
while( ${ln} <= $#lines + 1 )
{
# check ${lines[${ln}]} and manipulate ${ln} accordingly.
}
> I would suggest the following approach:
>
> # some bigger loop
> while (...) {
> my $line = "";
>
> while (<IN>) {
> if (/\\ex|\\begin{instructions}/) {
> seek IN, -length, 1;
> last;
> }
> $line .= $_;
> }
> }
>
On Wed, 30 Jun 2004 16:32:00 -0400 (EDT), Jeff 'japhy' Pinyan wrote
> On Jun 30, David Arnold said:
>
> >As I begin reading in lines from the file, I just print them until I hit a
> >line that has an opening "\ex" in it. At that point I want to accumulate
> >lines in one long string until I hit either "\begin{instructions}" or
> >another "\ex".
> >
> >$line.=<IN> #unless the current line coming in from IN is the start
> > #of a new \ex or a \begin{instructions}
> >
> >The difficulty is now I've read one line too many. I'd like to "put this
> >last line back" for the next round of reading while I process the
> >accumulated exercise lines.
>
> I would suggest the following approach:
>
> # some bigger loop
> while (...) {
> my $line = "";
>
> while (<IN>) {
> if (/\\ex|\\begin{instructions}/) {
> seek IN, -length, 1;
> last;
> }
> $line .= $_;
> }
> }
>
> This uses the seek() function to go to a position in the file. The last
> argument, 1, means we're moving relative to where we are now. The middle
> argument, -length, is the number of bytes to move. So if the line
> is 20 characters long, we're going 20 characters back from where we
> are now, essentially to the start of the line.
>
> --
> Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/
> RPI Acacia brother #734 http://www.perlmonks.org/ http://www.cpan.org/
> CPAN ID: PINYAN [Need a programmer? If you like my work, let me know.]
> <stu> what does y/// stand for? <tenderpuss> why, yansliterate of course.
>
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