Synopsis:

       len=strlen(str)        

Arguments:

       str - The string whose length to return                

Description:  This function returns the number of characters in the given str.

For example:

       string="The cat sat on the mat";

       // Count how many times "t" occurs

       int i;

       int tot;

       for (i=1,i<=strlen(string);i++)

               if(strsub(string,i,1) streq "t")

                       tot+=1;

               endif

       endif

       applog("Number of t's in string=",tot);

Returns:  Returns the number of characters in the given str.