SPUG: Grep syntax

Bill Campbell bill at celestial.com
Thu Jun 14 23:39:46 PDT 2007

Speaking of documentation, or lack thereof.

I just ran across a snippet of perl that I don't undertand at
all.  In this, the array @a contains octets of an IP address, and
it appears that the authoer wanted to set $start0.  As nears as I
can tell after trying various contents of @a, $start0 is changed
to 0 if there are *ANY* non-zero elements of the array @a.

grep { $start0=0 unless $_ == 0; } @a;

if ( ! $start0 ) { ...

It appears to me that this is a rather cryptic way of checking
that the array is empty or contains only 0 elements, and that the
grep command could be replaced with map or a simple loop.

INTERNET:  bill at Celestial.COM   Bill Campbell; Celestial Software LLC
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