In a nutshell, pam_timestamp caches successful authentication attempts, and
allows you to use a recent successful attempt as the basis for authentication.
When an application opens a session using pam_timestamp, a timestamp file is
created in the timestampdir directory for the user. When an application
attempts to authenticate the user, a pam_timestamp will treat a sufficiently-
recent timestamp file as grounds for succeeding.
tells pam_timestamp.so where to place and search for timestamp files. This
should match the directory configured for sudo(1) in the sudoers(5) file.
timestamp_timeout=number
tells pam_timestamp.so how long it should treat timestamp files as valid
after their last modification date. This should match the value configured
for sudo(1) in the sudoers(5) file.
verbose
attempt to inform the user when access is granted.
Users can get confused when they aren't always asked for passwords when running
a given program. Some users reflexively begin typing information before
noticing that it's not being asked for.