topic Re: Shell script: Logical operator precedence in Operating System - Linux

Shell script: Logical operator precedence

SGK — Mon, 26 Jun 2006 05:09:39 GMT

Hi All,

How to specify the precedence in the if/while loop?

In C,

if( ik || k
Like that, how to do the precedence in Shell script?

Thanks in advance.

Re: Shell script: Logical operator precedence

Sergejs Svitnevs — Mon, 26 Jun 2006 10:01:55 GMT

You can make logical expressions by grouping them with -a and -o operators (similar to the && and || operators).

if [ $i -lt $j ] && [ $j -gt $k -o $k -lt $i ] ; then
<...>
fi

Regards

Re: Shell script: Logical operator precedence

Peter Nikitka — Mon, 26 Jun 2006 11:15:35 GMT

Hi,

that depends on the shell you are using.
In ksh or bash you can use:

if [[ $i < $j && ($j > $k || $k < $i) ]]
then echo true
else echo false
fi

mfG Peter

Re: Shell script: Logical operator precedence

SGK — Mon, 26 Jun 2006 22:34:36 GMT

Hi,

Thanks all for the response.

Re: Shell script: Logical operator precedence

Peter Nikitka — Tue, 27 Jun 2006 01:50:24 GMT

Hi,

since you are new to this forum, I may put your attention to this:

http://forums1.itrc.hp.com/service/forums/helptips.do?#28

mfG Peter