lastModified: Gets the time when the file was last modified
Description
 Gets the time when the file was last modified. The time is returned as a POSIXct object.
Usage
"lastModified"(pathname, ...)
Arguments
pathname
A character string of the pathname to be checked. Value
 Returns POSIXct object specifying when the file was last modified.
 If the file does not exist or it is a directory, 0 is returned.
Symbolic links
This function follows symbolic links (also on Windows) and returns a
 value based on the link target (rather than the link itself).