Deleting lines from a file

[crasho2001]

Hi,

I am reading a log file regularly. I want to delete lines after reading. Size of log file will not increase any more.

How can I delete lines from a file without changing log file name?

 

[feherke]

Hi

Probably the tool you use rewrites the file. If the file's node number changes, it is not the same file anymore and applications which had it open and wrote into it will not be able to access it anymore until you restart them.

cat /dev/null > /log/file

Feherke.

http://rootshell.be/~feherke/

 

[crasho2001]

Hi,

"cat /dev/null" is an option but it will delete also unread lines. While I am reading the file, a new lines can be added.

For example I need to delete lines from 1 to 99.

Not the other ones.

Thank you.

 

[feherke]

Hi

Then

cp /log/file /tmp/watch-me
cat /dev/null > /log/file
less /tmp/watch-me

I mean, you can not remove just a part of a file on the fly.

Feherke.

http://rootshell.be/~feherke/