Convert URLs into HTML links using sed?

Question

I'm wondering if it's possible (recommended might be the better word) to use sed to convert URLs into HTML hyperlinks in a document. Therefore, it would look for things like:

http://something.com

And replace them with

<a href="http://something.com"&gt;http://something.com&lt;/a&gt;

Any thoughts? Could the same also be done for email addresses?

Answer 1

you can use awk

awk '
{
 for(i=1;i<=NF;i++){
   if ($i ~ /http/){
      $i="<a href=\042"$i"\042>"$i"</a>"
   }
 }
} 1 ' file

output

$ cat file
blah http://something.com test http://something.org

$ ./shell.sh
blah <a href="http://something.com"&gt;http://something.com&lt;/a&gt; test <a href="http://something.org"&gt;http://something.org&lt;/a&gt;

Answer 2

This might work.

sed -i -e "s|http[:]//[^ ]*|<a href=\"\0\">\0</a>|g" yourfile.txt

It depends on the url being followed by a space (which isn't always the case).

You could do similar for e-mails with.

sed -i -e "s|\w+@\w+\.\w+(\.\w+)?|<a href=\"mailto:\0\">\0</a>|g" yourfile.txt

Those might get you started. I suggest leaving off the -i option to test your output before making the changes inline.

Answer 3

sed -i.bakup 's|http.[^ \t]*|<a href="&">&</a>|'  htmlfile

Answer 4

While you could use sed, and I will typically only use sed if I need something that's write-only (that is, it only needs to work and doesn't need to be maintained).

I find the Python regular expression library to be more accessible (and gives the ability to add more powerful constructs).

import re
import sys

def href_repl(matcher):
    "replace the matched URL with a hyperlink"
    # here you could analyze the URL further and make exceptions, etc
    #  to how you did the substitution. For now, do a simple
    #  substitution.
    href = matcher.group(0)
    return '<a href="{href}">{href}</a>'.format(**vars())

text = open(sys.argv[1]).read()
url_pattern = re.compile(re.escape('http://') + '[^ ]*')
sys.stdout.write(url_pattern.sub(href_repl, text))

Personally, I find that much easier to read and maintain.

Answer 5

The file contain the following content

http://something.com

The following code will give the correct output

sed -r 's/(.*)/\<a href="\1">\1\<\/a\>/' file