How to handle new lines in textfield (CGI)

jonnyfolk has asked for the wisdom of the Perl Monks concerning the following question:

Got a bit of a prob:

I have a simple form with a few fields directed to a text file.
One of the fields is a textfield. When this is filled in without new line (carriage return) there is no problem and the field is recorded normally. However if the user uses the carriage return to begin a new line this starts a new line in the text file.
I have tried stripping out new lines and / or carriage returns but this strips out the whole response for that field.

my $address=$query->param('address');
my $address =~ s/\n/<br>/g;
my $address =~s/\r//g;
[download]

I'd be grateful for some help on this.

Comment on How to handle new lines in textfield (CGI) Download Code

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Re: How to handle new lines in textfield (CGI) by dga (Hermit) on Mar 28, 2003 at 23:47 UTC
One solution is to change the delimiter in your text file to something that will not be present in the input field. For example you could use a double linefeed to seperate records then single line feeds would not end your record. This has the obvious problem of what if the user enters a blank line. You could trim any double linefeeds out of course and this method retains the format that the user put the data into the form as a side effect. The problem with the current code which would be noted under `use warnings;` is that you are making up a new copy of address 3 times in the code. `my $address=$query->param('address'); $address =~ s/\n/<br>/g; $address =~ s/\r//g;` [download] See if that makes it better. warnings would say some thing similar to: my declaration masks variable in same scope.	[reply] [d/l] [select]
Re: Re: How to handle new lines in textfield (CGI) by jonnyfolk (Vicar) on Mar 29, 2003 at 07:44 UTC
Thanks very much for your input, dga. Removing the my's did the trick (why didn't I see that? Aaarrrghh!). I don't have warnings on this particular script because it is very large, not my own and didn't have warnings before. From the way it is written I think warnings would produce large plumes of black smoke from the back of my computer in no time:)	[reply]
Re: How to handle new lines in textfield (CGI) by perlguy (Deacon) on Mar 28, 2003 at 23:50 UTC
Here is a possible reason, as most everything looks good to me: `use warnings` or -w switch might have told you that "my" variable $address masks earlier declaration in same scope. change: `my $address =~ s/\n/<br>/g;` [download] to: `$address =~ s/\n/<br>/g;` [download] and your problem should be solved.	[reply] [d/l] [select]