How can I resize a file without rewrite it?

To grow the size is easy, just write some data to it. But how to reduce the size?! How can I open a file, that already exist, and just cut some data in the end without need to rewrite all of it?! Just imagine that the file can have 500Mb! I really can't rewrite it just to reduce the size.

Graciliano M. P.
"The creativity is the expression of the liberty".

In reply to Resize a File, without rewrite it! by gmpassos

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