jettero - Of course! I consider all sorts of options except for the obvious. If hold on to the value then I don't have to call stat() again.

Fletch - Thanks. I didn't know about the _ filehandle. It will probably be very efficient to check stat(_) since it is already present and being populated behind the secenes anyway.

I'll go benchmark these two approaches and see if there is any extra overhead to accessing _ with stat() versus keeping and populating my own scalar.

EDIT: Benchmarking shows that there is very little difference between the two methods. The only significant finding was that any method using one call (storing the timestamp to a scalar, stat()ing the auto-populated _ filehandle or even my original warning-prone check) is roughly twice as fast as stat()ing twice to check for existance then for a new timestamp.

With enough effort I was able to measure that storing to a scalar is about 1.5% faster than calling stat() on _. The warning-prone check is less than half a percent faster than that when the config file always exists and is about 5% slower when the config file is missing (even with STDERR closed so warnings don't go anywhere).

Bottom line: For my purposes the simplest/most direct method of storing the timestamp to a scalar then checking for definedness then difference is the most efficient method that shouldn't throw warnings. Thanks again.

In reply to Re: Most efficient File Modified check (w/o warnings) by Cefu
in thread Most efficient File Modified check (w/o warnings) by Cefu

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