UNIX for Advanced & Expert Users

Hiya.

I'm trying to create a script to diff between two web pages in a single line. This is partly just to improve my knowledge of the unix command-line, and cos it's an interesting problem.

First of all, the following command will output a web page's content to the command line:

Code:

> wget -q -O - http://aserver/file1.html

So, from there, I realised I could do this in two lines, if I didn't mind leaving a temporary file (which I do)

Code:

> wget -q -O tempfile.html http://aserver/file1.html
> wget -q -O - http://aserver/file2.html | diff - tempfile.html

What I want to know is, is there some way that I can do this on one line, without leaving any files behind? Like, can I write to a variable, or a temporary file handle, or something? E.g.:

Code:

> wget -q -O - http://aserver/file1.html > <FILEHANDLE>; wget -q -O - http://aserver/file2.html | diff <FILEHANDLE> -

(I know this doesn't work, it's just to illustrate the kind of thing I'd like to do).

Ta,
Robin.

If your shell supports process substitution (ksh93, zsh or bash),
you could use something like this:

Code:

diff <(wget -q -O - url1) <(wget -q -O - url2)

Yes, I am using bash, so that works fine

That's nice and intuitive. I didn't realise you could do that.

Thanks very much