find-filter is a filter for a list of file names read on standard input, and if the files match the
predicate their names are written on standard output.
The supported predicate forms are based on the file's creation time or modification time, and take the
form ctime or mtime followed by a time specification. A time specification takes the form of a + or -
followed by days (a non-negative integer), optionally followed by a colon (:) and hours (an integer in
the range 0 to 23), optionally followed by another colon (:) and minutes (an integer in the range 0 to
59).
The semantics of the time specification are that a file matches the predicate if the chosen time
attribute for the file is lessthan (+) the current time minus the time specification, else morethanorequalto (-) the current time minus the time specification. Alternatively, + means before the current
time minus the time specification, and - means at or after the current time minus the time specification.
find-filter is intended to be used to provide finer-grain and platform independent selection compared to
the -mtime or -ctime options of find(1). find-filter is expected to be used as a post-filter for the
output from find(1), and this is how it is used in the pmlogger_daily(1) scripts to select files to be
compressed or culled.