Congrats! You are almost there and you lack only small things.

Here are some pointers:

1. You haven't said anything about the shell you are using but somehow i doubt you are using a Bourne shell. More likely "/bin/sh" is a POSIX shell, a bash (Bourne Again Shell) or a ksh (Korn Shell). All these shells have an arithmetic facility and while what you do is syntactically correct using "expr" like you do is ancient, antiquated, deprecated and ultimately discouraged. See the "(( ... ))" in the man page of your shell and you will understand why.

2. The same goes for backticks: modern shells understand these only for purposes of backwards compatibility and using them has no advantages but a lot of disadvantages. Have a look in the man page for "$( ... )" as a device to execute a command in a subshell.

3. Your handling of the "num" variable: All usual shells allow variables to be used without having to declare them (unlike languages like C or PASCAL), but it is still good style to declare properly what you use prior to using it. Again, what you do is syntactically correct, but .... Using a line like

Code:

typeset -i num=0              # buffer to loop through arguments
typeset -i total=0            # buffer to sum up results

at the start of the script allows you to: give the variables a proper type, a sensible starting value and - even more important - to document their usage. If you look later at your code you will immediately know what you did by simply reading the comments.

OK, lets talk about this, then go on as you correct these errors. I will expand on this later.

I hope this helps.

bakunin