Append is ">>" (two >'s next to each other).

In other words, instead of this:

open FH, ">filename" or die "Bleah!\n$!";
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File level appending is opened like this:

open FH, ">>filename" or die "Bleah!\n$!";
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Have a look at perlopentut for details.

However, your code looks like it's trying to slurp in the file first, and then write it back out from scratch, while adding the new stuff at the end. Ok, that's one strategy, but it's not exactly the same thing as doing a file append.

As for your code, a better solution (since you also seem to be doing some processing on the current file, if it exists) would be this:

Open the input file. Open a temporary output file. Read the input file line by line. Process one line of input. Write it out to the output file. When done, append your additional information to the output file. Close the input file. Close the output file. Then rename your temp file so that it replaces your input file. Do your writing in standard ">" mode, because you're writing a new temp file, not appending to an existing file.

Open the input file. Open a temporary output file. Read the input file line by line. Process one line of input. Write it out to the output file. When done, append your additional information to the output file. Close the input file. Close the output file. Then rename your temp file so that it replaces your input file. Do your writing in standard ">" mode, because you're writing a new temp file, not appending to an existing file.

This is quite the long-winded approach. Why would you want to have to read and then write back out each line, even ones that are not being modified? Too much file input/output! Take a look at my solution. It simply scans the file once over and appends the data (if necessary) at the very end. Simple yet efficient.

This is quite the long-winded approach.

Long winded, eh?

perl -ni -e "BEGIN{ print qq/Enter new student's name:\n/; $name = <ST
+DIN> } next if /^\Q$name\E\b/; print $_ . ( eof ) ? $name : q// " myt
+est.doc
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Maybe you're right. ;)




Dave

Consider what will happen if this line fails (due to temporary disk full, for example):

        print FILE unless ( $_ =~ /^\Q$std\E\b/ );
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When you did open ">$stdInfo" you truncated the file, so if a print subsequently fails, you have permanently lost information from the $stdInfo file. You may not even know about it because you are not checking the return code from print or close. As already pointed out, opening in append mode seems best. If you must rewrite the whole file, write to a temporary file first, then rename after you are sure the rewrite has been successful.

- - arden.

Sometimes I just love doing homework :) If you plan on using this for a class, you'd better make sure you understand everything I've used. You wouldn't want a prof to ask "what does _that_ do?" and you end up blubbering a "I don't know what _that_ does".

#!c:/perl/bin/perl -w
$|++;

use strict;
use Fcntl ':flock';

print "Enter new student's name: ";
chomp( my $student = <STDIN> );

open my $fh, '+<', 'students.dat' or die "open failed: $!";
flock $fh, LOCK_EX or die "flock failed: $!";

my $found = 0;
while (<$fh>) {
   $found = 1 if /^\Q$student\E$/i;
}

print $fh $student, "\n" unless $found;

close $fh;
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Each line of the input file is probably going to look something like:

John Doe\n
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And your regex: /^\Q$student\E$/ will never match any line in that file, because it doesn't allow for the trailing newline. Thus, $student will always get printed, even if the name already exists. F




Dave

Did you even try running my script? If you had, you'd have seen that it works just fine. Notice the anchor I used. '$', not '\z'. So the match works just fine thank you.