'f' - FRESHEN FILES IN ARCHIVE(S)

The freshen command freshens one or more files in one or more archives,
although typically it is used to freshen files in only one archive.  The
freshening process replaces older files which already exist in the archive.
When replacing files, the 'last modification dates' of the files in the
archive are compared with those of their counterparts specified at the command
line, and the earlier modification date is assumed to represent the older
file.

As with the add command, only the file name component of the file is stored
by default.  The -x or -r options should be used to preserve path names.

The freshen command is almost identical to the update command, except that
the freshen command does not add any new files to the archive; it will only
freshen existing ones.  The replace command is similar to the freshen command,
except that it always replaces files in the archive, regardless of their
modification dates.