"+" stripped from CGI params

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

Hi all

I'm pretty sure that I'm missing something evident, but I can't see what. Why is the "+" character stripped from the CGI parameters?

use strict;
use warnings;
use CGI;

my $q = new CGI;
my $data = $q->param("gff");
print "$data\n";
[download]

For debugging I'm running the script from the command line :

perl perlcgi/getPlot.pl gff='kk_+ kk_-'
[download]

The output that I obtain is:

kk_ kk_-
[download]

Thanks in advance!

citromatik

Comment on "+" stripped from CGI params Select or Download Code

Replies are listed 'Best First'.
Re: "+" stripped from CGI params by jettero (Monsignor) on Dec 21, 2007 at 13:41 UTC
I think, traditionally, the '+' represents a space. I'm not sure what standard dictates this, but it seems to be the case. You can replace the '+' with a '%2b' to avoid it. Happily, CGI can do this for you if necessary: `my $encoded = $cgi_obj->escape("kk_+kk_");` [download] . -Paul	[reply] [d/l]
Re^2: "+" stripped from CGI params by ikegami (Patriarch) on Dec 21, 2007 at 13:55 UTC
I think, traditionally, the '+' represents a space. I'm not sure what standard dictates this, but it seems to be th I bet you'll find that the URI spec dictates that it must be escaped when it doesn't have a special meaning to the URI, as is the case here. One such special meaning was the seperation of keywords in a ISINDEX query (`script.cgi?these+are+keyworkds`). The query would have had whitespace at those spots, so it was common to replace `+`s with spaces.	[reply] [d/l] [select]
Re^3: "+" stripped from CGI params by amarquis (Curate) on Dec 21, 2007 at 14:20 UTC
Yep :) "Within the query string, the plus sign is reserved as shorthand notation for a space. Therefore, real plus signs must be encoded. This method was used to make query URIs easier to pass in systems which did not allow spaces."	[reply]
Re: "+" stripped from CGI params by hawtin (Prior) on Dec 22, 2007 at 13:56 UTC
I would suspect that this has to do with the different options for the `form`'s `enctype` when the `method` is `POST`. This controls the way the parameters are delivered to CGI, from memory: not-defined => "param1=one+value¶m2=another+val" "text/plain" => "param1=one value param2=another val" "multipart/form-data" => "param1=one value\nparam2=another val\n" My guess would be that since the default is to replace all spaces with "+" the CGI parameter processing by default does the reverse	[reply]


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