Scripting

11.2    Example: Web Server Monitoring

For this example, we want to use curl to measure the time it takes to download the home page of a website. The curl command is written in the following way:

time=$(curl --connect-timeout 2 -s -S -w '%{time_total}\n' \       -o /dev/null  2> /tmp/curl.error \       https://example.com) 

The various components of this command have the following meanings:

• --connect-timeout 2 aborts the connection setup attempt after 2 seconds.

• -s suppresses status outputs about the download progress.

• -S allows error outputs in deviation from this option.

• -w writes the runtime of the command to the standard output. This information ends up in the time variable.

• -o redirects the downloaded HTML file to /dev/null. Nothing is stored ...