An alternative: 
@files = qw(model4run1 modexl2run1 model4run2 model1run1);
my @array = split //,shift @files;
my @prefix;

foreach (@files) {
    @prefix = ();
    while ($c = shift @array) {
       next unless /^$c/;
       s/^$c//;
       push @prefix,$c;
    }
    @array = @prefix;
}
print join ""=>@prefix,"\n";

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In reply to Re: Find common prefix from a list of strings by artist
in thread Find common prefix from a list of strings by Albannach

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