How to strip out all of the links of an HTML file in Bash or grep or batch and store them in a text file

Question

I have a file that is HTML, and it has about 150 anchor tags. I need only the links from these tags, AKA, <a href="*http://www.google.com*"></a>. I want to get only the http://www.google.com part.

When I run a grep,

cat website.htm | grep -E '<a href=".*">' > links.txt

this returns the entire line to me that it found on not the link I want, so I tried using a cut command:

cat drawspace.txt | grep -E '<a href=".*">' | cut -d’”’ --output-delimiter=$'\n' > links.txt

Except that it is wrong, and it doesn't work give me some error about wrong parameters... So I assume that the file was supposed to be passed along too. Maybe like cut -d’”’ --output-delimiter=$'\n' grepedText.txt > links.txt.

But I wanted to do this in one command if possible... So I tried doing an AWK command.

cat drawspace.txt | grep '<a href=".*">' | awk '{print $2}’

But this wouldn't run either. It was asking me for more input, because I wasn't finished....

I tried writing a batch file, and it told me FINDSTR is not an internal or external command... So I assume my environment variables were messed up and rather than fix that I tried installing grep on Windows, but that gave me the same error....

The question is, what is the right way to strip out the HTTP links from HTML? With that I will make it work for my situation.

P.S. I've read so many links/Stack Overflow posts that showing my references would take too long.... If example HTML is needed to show the complexity of the process then I will add it.

I also have a Mac and PC which I switched back and forth between them to use their shell/batch/grep command/terminal commands, so either or will help me.

I also want to point out I'm in the correct directory

HTML:

<tr valign="top">
    <td class="beginner">
      B03&nbsp;&nbsp;
    </td>
    <td>
        <a href="http://www.drawspace.com/lessons/b03/simple-symmetry">Simple Symmetry</a>  </td>
</tr>

<tr valign="top">
  <td class="beginner">
    B04&nbsp;&nbsp;
  </td>
  <td>
      <a href="http://www.drawspace.com/lessons/b04/faces-and-a-vase">Faces and a Vase</a> </td>
</tr>

<tr valign="top">
    <td class="beginner">
      B05&nbsp;&nbsp;
    </td>
    <td>
      <a href="http://www.drawspace.com/lessons/b05/blind-contour-drawing">Blind Contour Drawing</a> </td>
</tr>

<tr valign="top">
    <td class="beginner">
        B06&nbsp;&nbsp;
    </td>
    <td>
      <a href="http://www.drawspace.com/lessons/b06/seeing-values">Seeing Values</a> </td>
</tr>

Expected output:

http://www.drawspace.com/lessons/b03/simple-symmetry
http://www.drawspace.com/lessons/b04/faces-and-a-vase
http://www.drawspace.com/lessons/b05/blind-contour-drawing
etc.

Answer 1

$ sed -n 's/.*href="\([^"]*\).*/\1/p' file
http://www.drawspace.com/lessons/b03/simple-symmetry
http://www.drawspace.com/lessons/b04/faces-and-a-vase
http://www.drawspace.com/lessons/b05/blind-contour-drawing
http://www.drawspace.com/lessons/b06/seeing-values

Answer 2

You can use grep for this:

grep -Po '(?<=href=")[^"]*' file

It prints everything after href=" until a new double quote appears.

With your given input it returns:

http://www.drawspace.com/lessons/b03/simple-symmetry
http://www.drawspace.com/lessons/b04/faces-and-a-vase
http://www.drawspace.com/lessons/b05/blind-contour-drawing
http://www.drawspace.com/lessons/b06/seeing-values

Note that it is not necessary to write cat drawspace.txt | grep '<a href=".*">', you can get rid of the useless use of cat with grep '<a href=".*">' drawspace.txt.

Another example

$ cat a
hello <a href="httafasdf">asdas</a>
hello <a href="hello">asdas</a>
other things

$ grep -Po '(?<=href=")[^"]*' a
httafasdf
hello