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linuxshelltimeraspberry-pignuplot

Extracting output of Linux "time" command into a file

I want to run the following Linux command a number of times in a loop and want to plot the variations in real time using gnuplot.

time scp -i k30.pem [email protected]:/home/ubuntu/pics/*  /home/pi/

But I am facing problem of how to extract the output of above command into a spreadsheet column so that i could plot it using gnuplot later. I am using latest version of Raspbian in my Raspberry Pi model 3B+.

Please help.

Solution

  • GNU time has -o FILE parameter that you can use to output the timing into a file. You can process the file, extract the timing from the file and put it somewhere in CSV or such in a loop.

    It also has -f format option that lets you customize the output format of the time.

    So, in your case it could go like this:

    /usr/bin/time -o mytime.log -f "%e" scp -i k30.pem [email protected]:/home/ubuntu/pics/* /home/pi/

    In this command the "%e" format makes the GNU time print only elapsed real time in seconds.