Preserving timestamp with -i switch

[umasuresh]

Hi Monks,
Is there a way to preserve the timestamp while backing up a file using the  -i switch?
e.g.

perl -e 's/old/new/g;' -pi.bak somefile

UPDATE Got it, thanks!
By default, this command preserves the timestamp!

[AR]

Please post what you found, so others searching for the same problem can learn from your solution.

[duyet]

Use -p option in cp to preserve mode, ownership, timestamp

for i in `find . -type f -print`; do cp -p $i ${i}_bk;done