Curl usage: Get the header and status code of the website

Curl usage: Get the header and status code of the website

The most common method for curl commands is to use parameter-I to obtain the header information of a domain name or IP address, including the HTTP return status code, server type, text type, and cache time; this method is also often used to determine whether the web Service is normal when monitoring web Services;

To monitor web services, you can use curl to obtain the header of the website and check whether the returned value is 200 OK. This serves as a standard for determining whether the web Service is normal;

Curl-I can be used to obtain the information. If the first line of information is extracted, there will be unnecessary information, how can we obtain it?

[Baby @ localhost ~] $ Curl-I mofansheng.blog.51cto.com
HTTP/1.1 200 OK
Server: Tengine
Date: Thu, 15 Oct 2015 06:10:17 GMT
Content-Type: text/html
Connection: keep-alive
Keep-Alive: timeout = 10
Vary: Accept-Encoding
Set-Cookie: PHPSESSID = 8c0bac037cf2cfd8b87e7dde079eb3bf; path =/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check = 0, pre-check = 0
Pragma: no-cache
Set-Cookie: lastvisit = 0% 091444889417% 09% 2Findex. php % 3F; expires = Fri, 14-Oct-2016 06:10:17 GMT; path =/; domain = .blog.51cto.com
If-Modified-Since: Sat, 10 Oct 2015 16:00:00 GMT
Load-Balancing: web48
Load-Balancing: web48

Use grep to filter the first line and find a lot of unnecessary information.

[Baby @ localhost ~] $ Curl-I mofansheng.blog.51cto.com | grep "OK"

% Total % Received % Xferd Average Speed Time Current

Dload Upload Total Spent Left Speed

0 0 0 0 0 0 0 --: -- 0

HTTP/1.1 200 OK

 

Solution:

Man curl: Check whether there are specific parameters that can meet our needs;

-S/-- silent

Silent or quiet mode. Don't show progress meter or error messages.

-S is the silent mode, indicating that no progress table or error message is output;

[Baby @ localhost ~] $ Curl-I-s mofansheng.blog.51cto.com | grep "OK"
HTTP/1.1 200 OK

A command to retrieve the 200 method:

[Root @ bkjia ~] # Curl-s-w "% {http_code}"-o/dev/null www.bkjia.com
200

Other methods: You can direct the error output to the system black hole for filtering.

[Baby @ localhost ~] $ Curl-I mofansheng.blog.51cto.com 2>/dev/null | grep "OK"
HTTP/1.1 200 OK
[Baby @ localhost ~] $ Curl-I mofansheng.blog.51cto.com 2>/dev/null | head-n1
HTTP/1.1 200 OK

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