edits the password file after setting the appropriate locks,
and does any necessary processing after the password file is unlocked.
If the password file is already locked for editing by another user,
will ask you
to try again later.
The default editor for
performs a number of consistency checks on the password entries,
and will not allow a password file with a
entry to be
rejects the new password file, the user is prompted to re-enter
the edit session.
Once the information has been verified,
to update the user database.
This is run in the background, and,
at very large sites could take several minutes.
Until this update
is completed, the password file is unavailable for other updates
and the new information is not available to programs.
Which type of cipher is used to encrypt the password information
depends on the configuration in
If the following environment variable exists it will be utilized by
The editor specified by the string
will be invoked instead of the default editor