How to profile a bash shell script?

Note : This work on recent GNU/Linux kernels.

For this kind of jobs, I wrote elap.bash (V2), to be sourced by the following syntax:

source elap.bash-v2

or

. elap.bash-v2 init

(See comments for full syntax)

So you could simply add this line at top of your script:

. elap.bash-v2 trap2

Little sample:

#!/bin/bash. elap.bash-v2 trapfor ((i=3;i--;));do sleep .1;doneelapCalc2elapShowTotal \\e[1mfirst total\\e[0mfor ((i=2;i--;))do tar -cf /tmp/test.tar -C / bin gzip /tmp/test.tar rm /tmp/test.tar.gzdonetrap -- debugelapTotal \\e[1mtotal time\\e[0m

Do render on my host:

0.000947481 Starting 0.000796900 ((i=3)) 0.000696956 ((i--)) 0.101969242 sleep .1 0.000812478 ((1)) 0.000755067 ((i--)) 0.103693305 sleep .1 0.000730482 ((1)) 0.000660360 ((i--)) 0.103565001 sleep .1 0.000719516 ((1)) 0.000671325 ((i--)) 0.000754856 elapCalc2 0.316018113 first total 0.000754787 elapShowTotal \e[1mfirst total\e[0m 0.000711275 ((i=2)) 0.000683408 ((i--)) 0.075673816 tar -cf /tmp/test.tar -C / bin 0.596389329 gzip /tmp/test.tar 0.006565188 rm /tmp/test.tar.gz 0.000830217 ((1)) 0.000759466 ((i--)) 0.024783966 tar -cf /tmp/test.tar -C / bin 0.604119903 gzip /tmp/test.tar 0.005172940 rm /tmp/test.tar.gz 0.000952299 ((1)) 0.000827421 ((i--)) 1.635788924 total time 1.636657204 EXIT

Using trap2 instead of trap as argument to source command:

#!/bin/bash. elap.bash-v2 trap2...

Will render two colons last command and total:

0.000894541 0.000894541 Starting 0.001306122 0.002200663 ((i=3)) 0.001929397 0.004130060 ((i--)) 0.103035812 0.107165872 sleep .1 0.000875613 0.108041485 ((1)) 0.000813872 0.108855357 ((i--)) 0.104954517 0.213809874 sleep .1 0.000900617 0.214710491 ((1)) 0.000842159 0.215552650 ((i--)) 0.104846890 0.320399540 sleep .1 0.000899082 0.321298622 ((1)) 0.000811708 0.322110330 ((i--)) 0.000879455 0.322989785 elapCalc2 0.322989785 first total 0.000906692 0.323896477 elapShowTotal \e[1mfirst total\e[0m 0.000820089 0.324716566 ((i=2)) 0.000773782 0.325490348 ((i--)) 0.024752613 0.350242961 tar -cf /tmp/test.tar -C / bin 0.596199363 0.946442324 gzip /tmp/test.tar 0.003007128 0.949449452 rm /tmp/test.tar.gz 0.000791452 0.950240904 ((1)) 0.000779371 0.951020275 ((i--)) 0.030519702 0.981539977 tar -cf /tmp/test.tar -C / bin 0.584155405 1.565695382 gzip /tmp/test.tar 0.003058674 1.568754056 rm /tmp/test.tar.gz 0.000955093 1.569709149 ((1)) 0.000919964 1.570629113 ((i--)) 1.571516599 total time 0.001723708 1.572352821 EXIT

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