That section on memory usage is very misleading. Tie::File keeps the index of every encountered lines (i.e. every lines up to the highest one read/written) in memory. In other words, if you do $tied[-1] or push @tied, ..., the index of every line in the file is loaded into memory (if they haven't already been loaded).

Tie::File is still a very useful module.

In reply to Re^2: How do I backtrack while reading a file line-by-line? by ikegami
in thread How do I backtrack while reading a file line-by-line? by mdunnbass

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