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Re: overwriting a file

by Sidhekin (Priest)
on Oct 30, 2007 at 11:15 UTC ( #647998=note: print w/replies, xml ) Need Help??


in reply to overwriting a file

As long as you open the file with mode >, the old contents should be gone already.

Assuming you are opening with mode +>, +< or similar (for read/seek/write combos, particularly useful with file locking), this is a real problem, and the solution you are looking for is truncate, probably with tell:

truncate( OPENFILE, tell(OPENFILE) );

(Alternatively, if you can safely truncate to 0 before you even start writing, that might be clearer.)

print "Just another Perl ${\(trickster and hacker)},"
The Sidhekin proves Sidhe did it!

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erix .oO( that sounds Boyer-Mooreish )
[Corion]: erix: Yes, but that's mostly for skipping characters you'll never read, but this approach skips the problem of needing to load more data while looking at a half-match
[Corion]: I mostly wonder how I can add this "reversal" to my toolchest, and if it's worth it or just clever
[choroba]: It should greatly simplify the parsing code, no flags or additional reading of the next buffer needed

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