topic Re: Strange sh Behavior in Operating System - Linux

Strange sh Behavior

spex — Tue, 20 Jun 2006 10:55:36 GMT

While working on a shell script which outputs time in HH:MM:SS format based on total seconds elapsed, I encountered something strange. I would appreciate it if someone could explain this behavior exhibited by sh-posix and sh-bourne under HP-UX 11.00:

# echo $(( 00 ))
0
# echo $(( 01 ))
1
# echo $(( 02 ))
2
# echo $(( 03 ))
3
# echo $(( 04 ))
4
# echo $(( 05 ))
5
# echo $(( 06 ))
6
# echo $(( 07 ))
7
# echo $(( 08 ))
sh: 08 : The specified number is not valid for this command.
# echo $(( 09 ))
sh: 09 : The specified number is not valid for this command.
# echo $(( 10 ))
10
# echo $(( 11 ))
11

ksh does not exhibit this behavior.

PCS

Re: Strange sh Behavior

James R. Ferguson — Tue, 20 Jun 2006 10:59:20 GMT

Hi:

A leading zero (0) in the a shell script specifies OCTAL values. Your first tip is that eight (8) isn't valid -- it isn't in octal :-))

Regards!

...JRF...

Re: Strange sh Behavior

spex — Tue, 20 Jun 2006 11:00:34 GMT

James,

Thank you!

PCS

Re: Strange sh Behavior

spex — Tue, 20 Jun 2006 11:04:19 GMT

Thread closed.

Re: Strange sh Behavior

Dennis Handly — Tue, 20 Jun 2006 16:26:55 GMT

JRF wrote:
>A leading zero (0) in the a shell script specifies OCTAL values

You can solve this by specifying the base:
echo $(( 10#08 ))