$SECONDS  –  Time since shell invocation

$SECONDS contains the seconds since the shell was invoked.

Links

• Z Shell manual

Examples

Shell uptime in seconds

1 2	sleep 2.5 echo ${SECONDS}s shel.l uptime

Output:

1	3s shell uptime

Shell uptime in seconds and milliseconds

1 2 3

sleep 2.5 typeset -F SECONDS echo ${SECONDS}s shel.l uptime

Output:

1	3.5948560000s shell uptime