Month: September 2020

I’ve learned how to check latency using curl today.

curl -w "\n 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\n" \
"https://www.google.com/"

Here is the sample result.

<SNIP HTML>
 time_namelookup:  0.022736
 time_connect:  0.040636
 time_appconnect:  0.075071
 time_pretransfer:  0.075225
 time_redirect:  0.000000
 time_starttransfer:  0.136858
 ----------
 time_total:  0.142189

Is it DNS? Connecting to the end point? Redirect? Starting the first byte transfer? This is a very good way to “guess” where the source of the latency is.