Wget: Skip download if file already exists?

Question

Answers to Skip download if files exist in wget? say to use -nc, or --no-clobber, but -nc doesn\'t prevent the sending of the HTTP req

Answer 1

The -nc option does what you're asking for, at least in wget 1.19.1.

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On my server, I have a file called index.html which contains links to a.html and b.html.

$ wget -r -nc http://127.0.0.1:8000/

Server logs show this:

127.0.0.1 - - [23/Mar/2017 17:51:25] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [23/Mar/2017 17:51:25] "GET /robots.txt HTTP/1.1" 404 -
127.0.0.1 - - [23/Mar/2017 17:51:25] "GET /a.html HTTP/1.1" 200 -
127.0.0.1 - - [23/Mar/2017 17:51:25] "GET /b.html HTTP/1.1" 200 -

Now I remove b.html and run it again:

$ rm 127.0.0.1\:8000/b.html
$ wget -r -nc http://127.0.0.1:8000/

Server logs show this:

127.0.0.1 - - [23/Mar/2017 17:51:38] "GET /robots.txt HTTP/1.1" 404 -
127.0.0.1 - - [23/Mar/2017 17:51:38] "GET /b.html HTTP/1.1" 200 -

As you can see, only a request for b.html was made.