Using a variable to keep state is a perfectly acceptable solution. But since TIMTOWTDI, here's one way to do the same using the flip-flop operator. I've also made several stylistic suggestions, since that's what I find "uncomfortable" about your original code ;-)

use warnings;
use strict;

my $file = $ARGV[0];
open my $fh, '<', $file or die "$file: $!";
while (<$fh>) {
    if ( (/test/..0) eq '1' ) {
        print "start\n";
    }
}
close $fh;
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