[Simple] Function arguments and return value

[Gao Chao]

I don't know how to write a function with arguments and return values
that are not scalars. I have learn to write something like

sub foo {
my $arg1 = shift;
my $arg2 = shift;

return $bar;
}

but I cannot pass lists or file handles like that. Can somebody
explain me how to pass lists and file handles as arguments and return
values of a function?

Thanks!

GC

 

[Amir Kadic]

but I cannot pass lists or file handles like that. Can somebody
explain me how to pass lists and file handles as arguments and return
values of a function?

You can pass (and return) lists by reference:

sub foo {
my $arrayref= shift;

print $$arrayref[0];
return $arrayref;
}


If you don't want to write $$arrayref all the time, you
can create local aliases, like this:

sub foo {
local (*array1,*array2,...) = @_; # can't use 'my' here

print @array1[0];
}

but you still have to pass array _references_ to the sub.

Filehandles can be 'passed' by passing typeglobs:

sub write {
local *GLOB= shift;
my @otherparameters= @_;

print GLOB @otherparameters;
}

write *STDIN,1,2,3;

You can also use references to typeglobs, the IO:File module, etc...


HTH
Amir