Here at plasmasturm I see the following little sub:

sub strip { s/\A\s+//, s/\s+\z// for my @r = @_; @r }

[download]

Formatting that out a bit, it's:

sub strip {
    s/\A\s+//, s/\s+\z// for my @r = @_;
    @r
}

[download]

So, I suppose it's stripping whitespace off of every element in @_. I see what the regexen are doing, but how is that "for" loop working? With the equals sign there ... I just don't get it. Regarding the comma, I suppose it's just a separator that tells perl to just evaluate one s/// after the other.

Further down in the code, there's this "for" loop:

for ( 1 .. 3 ) {
    run_fork { child {
        # [snip] some stuff ...
        exit;
    } }
}

[download]

Are run_fork and child function calls? They look strange to me. The only place I think I've ever seen functions that take a block of code after them is with map and grep... How does one write a sub that takes a block of code (in curlies) like that?

Actually, I've used {}'s to make hash refs for passing a handful of named params to a sub, but I don't think that's what's going on here...

In reply to How does this code work? (from "Perl is Unix") by Anonymous Monk

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