How do I measure request and response times at once using cURL?
From this brilliant blog post... https://blog.josephscott.org/2011/10/14/timing-details-with-curl/
cURL supports formatted output for the details of the request (see the cURL manpage for details, under -w, –write-out <format>
). For our purposes we’ll focus just on the timing details that are provided. Times below are in seconds.
-
Create a new file, curl-format.txt, and paste in:
time_namelookup: %{time_namelookup}s\n time_connect: %{time_connect}s\n time_appconnect: %{time_appconnect}s\n time_pretransfer: %{time_pretransfer}s\n time_redirect: %{time_redirect}s\n time_starttransfer: %{time_starttransfer}s\n ----------\n time_total: %{time_total}s\n
-
Make a request:
curl -w "@curl-format.txt" -o /dev/null -s "http://wordpress.com/"
Or on Windows, it's...
curl -w "@curl-format.txt" -o NUL -s "http://wordpress.com/"
What this does:
-w "@curl-format.txt"
tells cURL to use our format file-o /dev/null
redirects the output of the request to /dev/null-s
tells cURL not to show a progress meter"http://wordpress.com/"
is
the URL we are requesting. Use quotes particularly if your URL has "&" query string parameters
And here is what you get back:
time_namelookup: 0.001s
time_connect: 0.037s
time_appconnect: 0.000s
time_pretransfer: 0.037s
time_redirect: 0.000s
time_starttransfer: 0.092s
----------
time_total: 0.164s
Make a Linux/Mac shortcut (alias)
alias curltime="curl -w \"@$HOME/.curl-format.txt\" -o /dev/null -s "
Then you can simply call...
curltime wordpress.org
Thanks to commenter Pete Doyle!
Make a Linux/Mac stand-alone script
This script does not require a separate .txt file to contain the formatting.
Create a new file, curltime, somewhere in your executable path, and paste in:
#!/bin/bash
curl -w @- -o /dev/null -s "$@" <<'EOF'
time_namelookup: %{time_namelookup}\n
time_connect: %{time_connect}\n
time_appconnect: %{time_appconnect}\n
time_pretransfer: %{time_pretransfer}\n
time_redirect: %{time_redirect}\n
time_starttransfer: %{time_starttransfer}\n
----------\n
time_total: %{time_total}\n
EOF
Call the same way as the alias:
curltime wordpress.org
Make a Windows shortcut (aka BAT file)
Put this command in CURLTIME.BAT (in the same folder as curl.exe)
curl -w "@%~dp0curl-format.txt" -o NUL -s %*
Then you can simply call...
curltime wordpress.org
Here is the answer:
curl -X POST -d @file server:port -w %{time_connect}:%{time_starttransfer}:%{time_total}
All of the variables used with -w
can be found in man curl
.