Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/ltratt/multitime

Time command execution over multiple executions
https://github.com/ltratt/multitime

Last synced: about 2 months ago
JSON representation

Time command execution over multiple executions

Awesome Lists containing this project

README 

        
multitime: a better time utility

================================



Unix's `time` utility is a simple and often effective way of measuring how long a command takes to run. Unfortunately, running a command once can give misleading timings: the process may create a cache on its first execution, running faster subsequently; other processes may cause the command to be starved of CPU or IO time; etc. It is common to see people run `time` several times and take whichever values they feel most comfortable with. Inevitably, this causes problems.



`multitime` is, in essence, a simple extension to time which runs a command multiple times and prints the timing means (with confidence intervals), standard deviations, minimums, medians, and maximums having done so. This can give a much better understanding of the command's performance.



Why should you use multitime?

-----------------------------



If you want to do any of the following, then `multitime` is worth considering:



* You want to run a command several times to understand how its timings naturally vary.

* You want to run a command several times so that temporary blips in system activity do not distort the timings.

* You need different executions of a command being timed to have different inputs / outputs.

* You want to compare the timing of multiple commands (e.g. for benchmarking purposes).



`multitime` can also be used as a drop-in replacement for the POSiX time command: when invoked as time (e.g. via a symlink), `multitime` behaves as `time`. For most users, therefore, `multitime` can safely replace the time binary, even if you don't make use of its advanced features.



Example usage

--------------



The example below shows a simple benchmark of an `awk` program. In this case the program has been executed 5 times (`-n 5`).



    $ multitime -n 5 awk "function fib(n) \

    >   { return n <= 1 ? 1 : fib(n - 1) + fib(n - 2) } BEGIN { fib(30) }"

    ===> multitime results

    1: awk "function fib(n)   { return n <= 1 ? 1 : fib(n - 1) + fib(n - 2) } BEGIN { fib(30) }"

                Mean                Std.Dev.    Min         Median      Max

    real        1.860+/-0.0013      0.021       1.837       1.856       1.895

    user        1.833+/-0.0005      0.013       1.812       1.836       1.846

    sys         0.002+/-0.0000      0.003       0.000       0.000       0.008



Installing

----------



Formal released of `multitime` can be downloaded here: http://tratt.net/laurie/src/multitime/releases.html.



Formal releases can be built and installed with:



    $ ./configure

    $ make install



The latest source can be cloned with:



    $ git clone git://github.com/ltratt/multitime.git



and built with:



    make -f Makefile.bootstrap

    $ ./configure

    $ make install



Want to know more?

------------------



More details can be found at the http://tratt.net/laurie/src/multitime/