Bash script to check if a public HTTPS site is up [closed]

Question

I'm trying to setup another block of code to a bash script to check if a public website on HTTPS is up or not. Can we do this using CURL? Any suggestions what can be used besides CURL. Thanks

Answer 1

Here is a way to do it using wget instead of curl. Keep in mind that MacOS doesn't come with wget by default.

A successful web request will return a code of 200, a failure will return a 300, 400, 404, ect... (see REST API codes)

This line will return a 1 if the web request was successful, otherwise it will return 0

wget -q  -O /tmp/foo google.com | grep '200' /tmp/foo | wc -l
1

Answer 2

One of many:

if curl -s --head  --request GET https://example.com | grep "200 OK" > /dev/null; then 
   echo "mysite.com is UP"
else
   echo "mysite.com is DOWN"
fi

Answer 3

Nagios' check_http plugin can do this and much more, including checking for specific text in the response. You can run it from a shell script independently of Nagios itself:

$ check_http --ssl -H www.google.com -r 'Feeling Lucky'
HTTP OK: HTTP/1.1 200 OK - 11900 bytes in 0.086 second response time |time=0.085943s;;;0.000000 size=11900B;;;0

$ echo $?
0

Answer 4

Why not use a full solution for monitoring? I've found monit to be pretty good for this: http://mmonit.com/monit/

(this comes after years of using home brewed bash scripts - i've found monit to be more transportable to different boxes, and more robust than some messy scripts. Don't know about their paid version).

Answer 5

a similiar question was answered here:

https://stackoverflow.com/questions/12747929/linux-script-with-curl-to-check-webservice-is-up

The Qoute is from Burhan Khalid

curl -sL -w "%{http_code}\n" "http://www.google.com/" -o /dev/null

-s = Silent cURL's output

-L = Follow redirects

-w = Custom output format

-o = Redirects the HTML output to /dev/null

Example:

[~]$ curl -sL -w "%{http_code}\n" "http://www.google.com/" -o /dev/null

I would probably remove the \n if It were to capture the output.

so you just need to add -k in the options if you do not want to check for a valid certificate and use https instead of http obviously.

curl -sL -w "%{http_code}\n" "https://www.google.com/" -o /dev/null

reports the status code 200 with a return code of 0.

For everything else you need to define your response in the script.