How do I measure request and response times at once using cURL?

Question

I have a web service that receives data in JSON format, processes the data, and then returns the result to the requester.

I want to measure the request, response, and total time using cURL.

My example request looks like:

curl -X POST -d @file server:port 

and I currently measure this using the time command in Linux:

time curl -X POST -d @file server:port 

The time command only measures total time, though - which isn't quite what I am looking for.

Is there any way to measure request and response times using cURL?

Answer 1

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.

Answer 2

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.

1. 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 

2. 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 

I have not yet seen an option to output the results in microseconds, but if you're aware of one, post in the comments below.

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 

Then call it the same way as the alias:

curltime wordpress.org 

Make a Windows shortcut (aka BAT file)

Create a new text file called curltime.bat in the same folder as curl.exe and curl-format.txt, and paste in the following line:

curl -w "@%~dp0curl-format.txt" -o NUL -s %* 

Then from the command line you can simply call:

curltime wordpress.org 

(Make sure the folder is listed in your Windows PATH variable to be able to use the command from any folder.)