I want to determine the overlap between the end of one list and the beginning of another. I have a quick brute force solution, but prefer to use an existing module if one is available. I didn't find one when I searched metacpan, but that doesn't mean it doesn't exist.

# example
@list1 = qw(a b c);
@list2 = qw(b c d);
# a b c 
#   b c d
#   1 2
list_overlap( \@list1, \@list2 );
# returns 2

@list1 = qw(a b c d b);
@list2 = qw(b c d);
# a b c d b
#         b c d
#         1
list_overlap(  \@list1, \@list2 );
# returns 1

[download]

I don't know if this problem has a name.

Intended use is to combine two bash_history files captured on different dates into a single bash_history file that doesn't duplicate the overlap between the files. (Yes, if I set HISTFILESIZE to -1, then bash would maintain an unlimited history file.

__edit__ As pointed out, I should also specify that I want the largest overlap.

In reply to CPAN Module to determing overlap of 2 lists? by wazat

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