How do I delete records in an active log file "in -place"

[kat000003]

I have an active log file with date records in it.
I want to delete all records prior to a given date BUT I need to do so "in-place" because the file is currently being written to ?
If I use standard awk or head|tail commands, I lose records that get written at the time of the cleanup.

 

[taupirho]

Since you haven't received any answers here's my tuppence-worth.

It seems clear you have two choices - either you stop writing to this file whilst you do your housekeeping on it OR store the log records in a database instead. Assuming you're using UNIX or a derivative some of these already come with a built-in database system that, although simple, might meet your needs.

Try man dbm for more info.