CHPASS(1) BSD General Commands Manual CHPASS(1)NAME
chpass, chfn, chsh, — add or change user database information
SYNOPSISchpass [-a list] [-p encpass] [-e expiretime] [-s newshell] [user]
The chpass utility allows editing of the user database information asso‐
ciated with user or, by default, the current user.
The chfn, and chsh utilities behave identically to chpass. (There is
only one program.)
The information is formatted and supplied to an editor for changes.
Only the information that the user is allowed to change is displayed.
The options are as follows:
-a The super-user 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. [Note that
this only changes the user database, master.passwd.]
-p The super-user is allowed to directly supply an encrypted pass‐
word field, in the format used by crypt(3), as an argument. [See
the discussion in getpwent(3) about types of passwords; this
option may not be appropriate.]
Change the account expire time. This option is used to set the
expire time from a script as if it was done in the interactive
Attempt to change the user's shell to newshell.
Possible display items are as follows:
Login: user's login name
Password: user's encrypted password [do not use this to
change a password; use passwd(1) instead]
Uid: user's login
Gid: user's login group
Class: user's general classification
Change: password change time
Expire: account expiration time
Full Name: user's real name (*)
Home Directory: user's home directory
Shell: user's login shell
NOTE(*) - Historically, the so-call "GECOS" field in the
user database entry contain the full name plus
other information. Only the full name is cur‐
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.
Do not use this to change a password; use passwd(1) instead.
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 id's, 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 class field references class descriptions in /etc/login.conf and is
typically used to initialize the user's system resource limits when they
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 full name field contains the full name of the user.
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 alter‐
ing a login shell, and not the super-user, 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.
Once the information has been verified, chpass uses pwd_mkdb(8) to update
the user database.
LOOKUPD AND DIRECTORY SERVICE AWARENESS
User database entries (among other things) are under the control of
lookupd(8) and may be physically located in many different places,
including local and remote netinfo(5) databases, directory service agents
such as LDAP servers and flat file databases such as master.passwd. This
version of chpass is currently limited to changing user database entries
in the flat file and local netinfo databases.
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 super-user, may edit the information associated with the user.
See pwd_mkdb(8) for an explanation of the impact of setting the
PW_SCAN_BIG_IDS environment variable.
/etc/master.passwd the user database
/etc/passwd a Version 7 format password file
/etc/chpass.XXXXXX temporary copy of the password file
/etc/shells the list of approved shells
SEE ALSOfinger(1), login(1), passwd(1), getusershell(3), login.conf(5),
passwd(5), pwd_mkdb(8), vipw(8)
and Robert Morris and Ken Thompson, UNIX Password security.
User information should (and eventually will) be stored elsewhere.
The chpass utility appeared in 4.3BSD-Reno.
BSD December 30, 1993 BSD