Monday, September 23, 2013

Check url for http response codes with curl

A little linux helper to check the status of urls in a sitemap, based on the server response code.

Currently redirects are said to be not good for Bing ranking, neutral for Google. We want to rank in both, so we don't want 300s, and sure no 400s or 500s - the error response codes.

For this example from work I use curl, easy and fast, and  "".

curl -D - 

-D - means dump header into file - meaning stdout.
LONG result, but direction is correct.
Now add a -o /dev/null, meaning move content into output /dev/null.

curl -D - -o /dev/null
Still too long, but getting closer.
So I'll use sed to print just the header response, based on the regex HTTP:
curl -D - -o /dev/null | sed -n '/HTTP/p'

STILL not there. Adding -s to curl to silence the speed-o-meter gives me:

curl -s -D - -o /dev/null | sed -n '/HTTP/p'

results in: HTTP/1.1 200 OK

Got it!
It sure has limitations, this is not going to help identify server level rewrites or reverse proxy redirects without intermediate non 200 http response, nor is it going to identify a http-refresh. I still find it pretty helpful. The first is still good to submit to the Search Engines, and the second is rare, fortunately, at least where I work.

This again is patched together from a variety of sources, including stackoverflow, a sed post by Eric Pemment and little bits from Andrew Cowie (yep, that's about apis, but still helped): thanks everyone!

Thanks Andy, this is a great addition you suggest in the comments to add the L to follow redirects! I would then extend the sed to get this:
curl -s -L -D - -o /dev/null | sed -n '/HTTP\|Location/p' 
follows redirects, and with the extended sed we see the url and the http response like this:

HTTP/1.1 302 Found Location:
HTTP/1.1 301 Moved Permanently Location: /support/my-support
HTTP/1.1 301 Moved Permanently Location: /support/my-support/us/en/19
HTTP/1.1 200 OK

1 comment:

  1. adding --location to the command will allow curl to follow through the redirect to the final destination. This is great for shortened URLs.


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