Changing .html to .asp on some links but not others

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

Im doing content migration (pushing the content of one set of web pages in .html format to another set of pages in .asp format) and while doing that I need to change certain links from the old site from having a .html extension to having a .asp extension. Some links are links to external sites that I do not want to have changed from .html to .asp. The only thing these links have in common is that the have http:// in the beginning and .html at the end. So I need to search for those two keys, and when I find them, I just need to leave the line alone. Here is the code I am using now.

          

    open (FILE, $filename);
    while(<FILE>){
        

        # walk each file
        my $line = $_ ;
        chomp $line;

        
        #grabbing and printing everything between the body tags
        if (/<body.*?>/i ... /<\/body.*?>/i){
         # this is a body line
          # extract the body
         
        
##########################3
######  this is where i need to put an if else statement that does not
+hing if http:// and .html are found in the same line
        ##Changing .html to .asp at the end of every link that do not 
+belong to an external link
         s/(href=.+?\.)html/$1asp/gi;

         $body_temp = $_;
         $body_temp =~ s/(.*?)\<body\>(.*?)\<\/body\>/$2/i;
         chomp($body_temp);

         $body = "$body_temp" ;
        
         # Write the body to the output file
         print OUTFILE $body . "\n";
        }
    }
    close(FILE);
[download]

Comment on Changing .html to .asp on some links but not others Download Code

Replies are listed 'Best First'.
(tye)Re: Changing .html to .asp on some links but not others by tye (Sage) on May 02, 2001 at 01:00 UTC
First, you really should fix your web pages to put quotes around your hrefs: `s/href=([^"\s>]+)/href="$1"/g` because your current code will fail for cases like: `<a href="http://www.google.com/">Google</a> uses .html files.` to name just one of many problem cases. Easy way: `s/(href="[^"])\.html"/$1.asp"/g s/(href="http://[^"])\.asp"/$1.html"/g` [download] but that breaks if you already have some external links that end in ".asp". Better: `s{(href="[^"]*\.html")}{ my $s= $1; $s =~ s#\.html"$#.asp"# unless $s =~ m#^http:#; $s }ge;` [download] Oh, and I hope you don't have href=x outside of `<a>` tags in any of your web pages. (: - tye (but my friends call me "Tye")	[reply] [d/l] [select]
Re: Changing .html to .asp on some links but not others by Anonymous Monk on May 02, 2001 at 01:18 UTC
Learn to use HTML::Filter. It might take a bit of work to figure it out, but it's worth it.	[reply]
Re: Changing .html to .asp on some links but not others by how do i know if the string is regular expression (Initiate) on May 02, 2001 at 01:07 UTC
Try `s/(href=(?!['"]?http:\/\/).+?\.)html/$1asp/gi;` I used the negative lookahead (`(?!...)`) to catch the "http://". Yay, Mastering Regular Expressions. - FrankG	[reply] [d/l] [select]
Re: Changing .html to .asp on some links but not others by astanley (Beadle) on May 02, 2001 at 00:50 UTC
You need to add a regex check in the spot where you already determined it should be. I recommend it look like this: `if ($_ !~ m/href=\"http:\/\/.+\.html/) { s/(href=.+?\.)html/$1asp/gi }` [download] Warning: the regex is untested but I believe it should work provided the links have quotations around the URL's. -Adam Stanley Nethosters, Inc.	[reply] [d/l]
Re: Re: Changing .html to .asp on some links but not others by isotope (Deacon) on May 02, 2001 at 01:15 UTC
Given that he's reading one line at a time, this solution says: `If the current line does not contain the string href="http://[anything].html then replace every instance (on this line) of href=[anything].html with href=[anything].asp` [download] If there are multiple links on one line, and any one of them is external, this solution will skip all links on that line. If a link spans more than one line, it will not be handled properly. After looking at this same problem posted here what, 4 times now, I'm thinking maybe the best approach is to use HTML::TokeParser, analyze each link (using the convenient `get_tag` method), and rewrite the HTML with CGI or something so it's nice and pretty. --isotope http://www.skylab.org/~isotope/	[reply] [d/l]