speedtests

Some small tests about execution speed.

Usage

make

Warning: This pulls submodules, compiles all binaries and runs all test scripts.

Tests

A short list of all tests present here

prepend-script.ksh

This script checks timings for the typical one-liners which prepend some string to some output in a shell script. See http://serverfault.com/questions/72744/command-to-prepend-string-to-each-line

The Makefile uses shcomp from ksh to speed this script up. But it runs in any bourne shell type. If you want to see how slow bash is compared to this, then run it directly.

Results (Linux, Debian 7.x):

• If you do not have a special purpose statically linked binary for the task, stick with something like awk -v T="[TEST]" '{ print v " " $0 }' It is easy to understand, easy to use, flexible and performs very well.

• If you happen to compile your ksh script anyway, then perhaps do it directly in your ksh. It still is a factor slower than awk, but is less fork intensive, which is interesting. But if you do not compile your script - which is the normal case - stick with awk!

• Next comes sed 's/^/[TEST] /'n which is less flexible than the awk script, and a bit slower.

• perl -ne 'print "[TEST] $_"' is nearly as fast as sed but takes a bit more time. perl is a lot more powerful than sed, though, but most time the power of awk is enough for all needs.

• python in the uncompiled form is very slow. Compiled python was not tested as it is usually not used in the given scenario.

• The shell variant while read line; do echo "[TEST] $line"; done is the slowest variant if the shell script is not compiled. Only use this if there are only a few lines or you have less than 1 line per second in average.