Displaying an array in a cgi generated textarea

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

Fellow Monks,
I have a text file that I'd like to display in a form textarea. I read this file into an array @source, and put that into the textarea of my cgi script...

use CGI;
$co=new CGI;
#some code here
$co->center($co->textarea
(
-name=>'textarea',
-default=>"@source",
-rows=>20,
-columns=>80,
)),
#other code here
[download]

The problem is that while the first line displays fine, all the subsequent lines are shifted to the right by one space. I think it may be because the array is in between quotation marks (I could be wrong though!). However, when I get rid of the quotation marks it really messes up the order of the elements in the array. It seems to display to the text area like this:
print "@source";
and what I want it to do is display the array like this:
print @source;
I'd appreciate an ideas or suggestions.
Martymart

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Re: Displaying an array in a cgi generated textarea by fruiture (Curate) on Feb 27, 2003 at 18:18 UTC
An array in double quotes (which equals qq//) is interpolated and the result is ... `print "left @array right"; # try perl -MO=Deparse for that: print 'left '.join($",@array).' right'` [download] So you see, perl uses $" as the seperator of the array elements, $" is by default just a single space character, you can simply change that. Use local() to avoid problems with other code, because CGI.pm afaik uses $", too. `local $" = ''; #... -default => "@source", #... #or even -default => do { local $" = ''; "@source" }, #or better -default => join('',@source)` [download] HTH, see perlvar -- http://fruiture.de	[reply] [d/l] [select]
Re: Re: Displaying an array in a cgi generated textarea by martymart (Deacon) on Feb 27, 2003 at 18:31 UTC
Thanks fruiture, just tried it... works great, valuable lesson learned... Martymart	[reply]
Re: Displaying an array in a cgi generated textarea by pfaut (Priest) on Feb 27, 2003 at 18:25 UTC
When you read the file into the array, you read the line terminators as well. Those line terminators start a new line in the textarea, too. When you interpolated the array into a string with `-default=>"@source"`, perl used the value of $" (a space by default) to separate the elements. This is where the extra space came from on the second and subsequent lines. There are a couple of ways I can think of to fix this. Choose one of these to suit your tastes. Use `chomp @source` to remove the newline characters before interpolating into the string. This will allow the textarea to rewrap the text. Set $" to an empty string before the interpolation. This will keep the current line breaks when loaded into the textarea. You might want to use `local ($") = ""` here. The local will reset $" back to its previous value when your program leaves the current scope. `--- print map { my ($m)=1<<hex($_)&11?' ':''; $m.=substr('AHJPacehklnorstu',hex($_),1) } split //,'2fde0abe76c36c914586c';` [download]	[reply] [d/l] [select]