While Loop

[mosama1]

I want ti know if this script is true or not

while [ $RET -ne 0 || $RET -ne 3 ];
do
RET=$?
done

 

[hoinz]

Did you assign a value to $RET before running this piece of code?
If the answer is no, then your code is the same as:

while [ -ne 0 || -ne 3 ];
do
RET=$?
done

And that's a syntax error obviously.

 

[feherke]

Hi

while [ $RET -ne 0 [red]||[/red] $RET -ne 3 ][red];[/red]
do
    RET=$?
done

[tt][red]||[/red][/tt] - wrong, use [tt]-o[/tt] instead
[tt][red];[/red][/tt] - wrong, not needed
Beside this, the [tt]while[/tt] is pointless, an [tt]if[/tt] would be enough. ( Unless you really want to run into an endless loop. )

Feherke.

http://rootshell.be/~feherke/

 

[mosama1]

Yes the value of $RET is assigned i ask about this line of code

while [ $RET -ne 0 || $RET -ne 3 ];

is true

 

[hoinz]

feherke spotted it.

 

[mosama1]

how to spotted it

 

[PHV]

man test

Furthermore, ANY value of $RET is either different from 0 or different from 3, so the logic seems broken ...

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[mosama1]

what is the different between || and -o

 

[PHV]

Again, man test

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[mosama1]

Thanks to both of you

 

[SamBones]

I agree with PHV, the logic is broken. It should be a logical "and", not a logical "or".

 

[geirendre]

Probably a common mistake to make, mixing up && or ||
in such a test....
It might be helpfull to use a "Truth table"
to see if the desired result is accomplised.

http://en.wikipedia.org/wiki/Truth_table

HTH