If you are on a Unix, POSIX, Windows + cygwin (or some other package with Unix tools), VMS + whatever the name of their Unix tools package is, or some other decent system, you could speed up your program, while bringing it down to one line: 
    system "sort in_file > out_file";

[download]
Unix sort is specially equiped to sort large files (large on disk compared to available RAM).

Abigail

In reply to Re: sorting large data by Abigail-II
in thread sorting large data by thealienz1

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