How to adjust time command to measure a program elapsed time

benchmarkctime

I'm trying to get the time that my program takes to finish (aka elapsed time) so I'm using the common time.

What I get by doing this is 3 measurements: user, system and total. This is fine but I found that the user time that I'm interested in has only two decimal places and I would need more. Is there any way I can get more decimal places out of my time command?

Example: time ./myCProgram
Output: 0.17s user 1.21s system 130% cpu 0.187 total

Wished output wanted: 0.17000s user 1.21s system 130% cpu 0.187 total
(or more decimal places)

Best Answer

If all you want is elapsed time, then with zsh or ksh93:

$ typeset -F SECONDS=0; sleep 1; print "$SECONDS"
1.0012850761

Now, whether that kind of precision makes sense is another matter.

Related Solutions

Command Line – Command to Monitor Elapsed Time in Background

You may try a shell script (call it timer.sh) like this:

. timer.val

case "$1" in 
  start)
   echo $TIMERSTART
   echo "TIMERSTART=`date +%s`" > timer.val
   echo $TIMERSTART
   ;;
  stop)
   echo $TIMERSTART
   TIMEREND=`date +%s`
   echo $TIMEREND
   let RESULT=$TIMEREND-$TIMERSTART
   echo $RESULT
   ;;
  *)
   echo "no command"
esac

Understanding PS Elapsed Time Format for Long Running Processes

According to the standard:

In the POSIX locale, the elapsed time since the process was started, in the form:
[[dd-]hh:]mm:ss
where dd shall represent the number of days, hh the number of hours, mm the number of minutes, and ss the number of seconds. The dd field shall be a decimal integer. The hh, mm, and ss fields shall be two-digit decimal integers padded on the left with zeros.

So, the 9 means days, whether you believe it or not. Could you be misinterpreting the output from htop? What does top (which has a time format of minutes:seconds) say? Are you certain that the field you are looking at in htop is equivalent to etime? (for example, could it means 126 minutes of CPU time?)

Best Answer

Related Solutions

Command Line – Command to Monitor Elapsed Time in Background

Understanding PS Elapsed Time Format for Long Running Processes

Related Question