Home / server / Questions / 316953
Accepted
user9474
Asked: 2011-09-30 10:16:44 +0800 CST

How to output the real time a command takes (and nothing else)?

  • 772

How can I output the real time a command takes (and nothing else)?

Example:

This won't work:

$ time -p sleep 2 | grep real
real 2.00
user 0.00
sys 0.00

I want something like:

$ print-real-time sleep 2
2.00
unix

3 Answers

  1. Best Answer

    You need to capture the output of time first. Then you can process it.

    • 5

  2. A non-BASH-specific solution (explicitly use /usr/bin/time so it's not the pipe-gobbling bash builtin) --

    /usr/bin/time -p some_command_or_subshell 2>&1 | grep real | awk '{print $2}'

    Depending on the delicate nature of whatever you feed this output to you may want to redirect the output of your subject command to /dev/null...

    • 3

  3. Here's a hacky solution using cut to split the fields.

    time -p sleep 2 | grep real | cut -f2 -d' '

    You can also use awk:

    time -p sleep 2 | grep real | awk '{ print $2 }'
    • 0