Shell Programming and Scripting

Hi,

I am having a bit of trouble writing this.

I have the script working if I only use 1 of these but it's not working the way i need it to.

Basically more above the script i may or may not have a 5th variable defined. if i do it does a process before getting to the rest of the script. if there is not a 5th variable it skips that if statement and moves on.

Now the problem I am having is I need to have a check to make sure that the person using the script has 4 or 5 variables defined depending on which part of the script they are using.

When it checks how many variables it has it keeps complaining about this part:

Code:

        if [[ $# -ne 4 ]] || [[ $# -ne 5 ]]
        then

for some reason if there is a 5th variable the script is only trying to find 4 not or 4 or 5.

Can someone correct me here? I tried a few things and nothing seemed to do the trick.

The conjunction of the set of integers not equal to 4 and the set of integers not equal to 5 is the set of all integers. Put another way, the expression x != 4 || x != 5 is always true. For that expression to evaluate falsely would require the existence of an integer that is simultaneously equal to 4 and equal to 5.

If the goal is for the expression to only evaluate to true when x is any value except 4 or 5, then you need to use &&.

Regards,
Alister

Hi.

Possibly of use: http://en.wikipedia.org/wiki/De_Morgan%27s_laws ... cheers, drl