add or change user database
chpass allows editing of the user database
information associated with user, or, by default, the
current user. The information is formatted and supplied to an editor for
Only the information that the user is allowed to change is displayed.
The options are as follows:
- The superuser is allowed to directly supply a user database entry, in the format specified by passwd(5), as an argument. This argument must be a colon (‘:’) separated list of all the user database fields, although they may be empty.
- Attempts to change the user's shell to newshell.
Possible display items are as follows:
- user's login name
- user's encrypted password
- user's login
- user's login group
- password change time
- account expiration time
- user's general classification
- Home Directory:
- user's home directory
- user's login shell
- Full Name:
- user's real name
- Office Location:
- user's office location
- Office Phone:
- user's office phone
- Home Phone:
- user's home phone
The login field is the user name used to access the computer account.
The password field contains the encrypted form of the user's password.
The uid field is the number associated with the login field. Both of these fields should be unique across the system (and often across a group of systems) as they control file access.
While it is possible to have multiple entries with identical login names and/or identical user IDs, it is usually a mistake to do so. Routines that manipulate these files will often return only one of the multiple entries, and that one by random selection.
The group field is the group that the user will be placed in at login. Since BSD supports multiple groups (see groups(1)), this field currently has little special meaning. This field may be filled in with either a number or a group name (see group(5)).
The change field is the date by which the password must be changed.
The expire field is the date on which the account expires.
Both the change and expire fields should be entered in the form month day year where month is the month name (the first three characters are sufficient), day is the day of the month, and year is the year.
The class field specifies a key in the login.conf(5) database of login class attributes. If empty, the “default” record is used.
The user's home directory is the full UNIX path name where the user will be placed at login.
The shell field is the command interpreter the user prefers. If the shell field is empty, the Bourne shell (/bin/sh) is assumed. When altering a login shell, and not the superuser, the user may not change from a non-standard shell or to a non-standard shell. Non-standard is defined as a shell not found in /etc/shells.
The last four fields are for storing the user's full name, office location, and work and home telephone numbers.
Once the information has been verified,
pwd_mkdb(8) to update the user database.
The vi(1) editor will be used unless the environment variable
EDITOR is set to an alternate editor. When the
editor terminates, the information is re-read and used to update the user
database itself. Only the user, or the superuser, may edit the information
associated with the user.
- user database
- user database, with confidential information removed
- lock file for the passwd database
- list of approved shells
- temporary copy of the user passwd information
- Attempting to lock password file, please wait or press ^C to abort
The password file is currently locked by another process;
chpasswill keep trying to lock the password file until it succeeds or the user hits the interrupt character (control-C by default). If
chpassis interrupted while trying to gain the lock any changes made will be lost.
If the process holding the lock was prematurely terminated the lock file may be stale and
chpasswill wait forever trying to lock the password file. To determine whether a live process is actually holding the lock, the admin may run the following:
$ fstat /etc/ptmp
If no process is listed, it is safe to remove the /etc/ptmp file to clear the error.
finger(1), login(1), passwd(1), getusershell(3), login.conf(5), passwd(5), pwd_mkdb(8), vipw(8)
Robert Morris and Ken Thompson, Password security: a case history, Communications of the ACM, Issue 11, Volume 22, 594–597, Nov. 1979.
chpass command appeared in