The $* allows you to iterate over all of the tokens contained within $1-. The way this works is much like a while loop. $* has been omitted from the help file since while loops were introduced.
$* is extremely powerful, because it is much faster than using a while loop on a list of tokens. Understanding how this works is pretty simple, so consider the following:
This can be written as:
The above is much smaller, and a lot faster. Pretty cool, isn't it?
Notes & quirks
Why was the $* identifier removed from the help file in the first place? Well, $* was removed because it does not really work the same way that the other identifiers do, and because it is quirky.
Quirky? Quirky, how?
Well, mIRC takes the command $* appears in, and replaces all of the occurrences in the line by a special marker: `~$*: An example of how this is accomplished is shown below:
Further examining the code, it is easy to understand why the above returns such a value:
//tokenize 32 abcd | echo -a $mid($*,2)
Why isn't this returning bcd? Because of the usage of the special marker `~$*, mIRC has stored the command as actually echo -a $mid(`~$*,2).
Then, for each token (here only $1 == abcd), mIRC evaluates the line. $mid(`~$*,2) becomes ~$*, and then mIRC replaces the marker by the token and executes the echo command. However, after an operation like $mid in this example, that marker cannot be found. Basically, it cannot be guaranteed that the correct value of $* inside an identifier can be found.
There is a workaround for the above issue, and that is by using scid and scon:
//tokenize 32 abcd | scon -r echo -a $!mid( $* ,2)
mIRC replaces $* by the marker, but scon has an extra evaluation system which fits perfectly. The $* mechanism is enabled on scon, and mIRC stores the command of the $* as scon -r echo -a $!mid( `~$* ,2) mIRC then evaluates the line for each token, which then becomes: "scon -r echo -a $mid( abcd ,2)" Finally, the scon command is executed, resulting in the expected value being echoed.
Another issue is that you cannot call $* more than once in the same scope; the command will simply be skipped. However, this can also be circumvented/worked-around :) Simply retokenize after using $*, which forces the update of $1- $* can now be used again, but only if the number of tokens passed is higher than the previous number of tokens passed. $* will only start from the previous number of tokens + 1:
//tokenize 32 1 2 3 | echo -a $* | tokenize 32 4 5 6 7 8 | echo -a $* | echo -a here
The first three tokens of the second tokenize, "4 5 6", are dummy tokens which are passed to fill in the gap. $1- can be used in front of the next tokenize command in order to start from those new tokens, much like a normal situation.