passwd(4)passwd(4)NAMEpasswd - Password files
DESCRIPTION
A passwd file is a file consisting of records separated by newline
characters, one record per user, containing seven colon (:) separated
fields. These fields are as follows:
User's login name. The default length is 8 characters. User's
encrypted password. User's ID User's login group ID General informa‐
tion about the user User's home directory User's login shell
The name field is the login used to access the computer account, and
the uid field is the number associated with it. They should both be
unique across the system (and often across a group of systems) since
they control file access.
While it is possible to have multiple entries with identical login
names and/or identical user gid'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 login name must never begin with a hyphen (-); also, it is strongly
suggested that neither uppercase characters or dots (.) be part of the
name, as this tends to confuse mailers. No field may contain a colon
(:) as this has been used historically to separate the fields in the
user database.
The password field is the encrypted form of the password. If the pass‐
word field is empty, no password is required to gain access to the
machine. Because these files contain the encrypted user passwords, they
should not be readable by anyone without appropriate privileges.
Use the vipw command to edit password entries. This ensures that the
hashed password database is rebuilt.
Security Note
If you have enhanced security installed on your system, the password
field contains an asterisk (*). The encrypted password is stored in the
user's protected password database.
The gid field is the group that the user will be placed in upon login.
Since the operating system supports multiple groups (see the groups
command) this field currently has little special meaning.
The gecos field normally contains comma (,) separated subfields as fol‐
lows:
User's full name User's office number User's work phone number User's
home phone number
This information is used by the finger command.
The user's home directory is the full UNIX pathname where the user will
be placed on login.
The shell field is the command interpreter the user prefers. If the
shell field is empty, the Bourne shell (/bin/sh) is assumed.
The allowable values for the UID are unsigned numbers from 0 to 65535.
The command pwck can be used to verify the accuracy of data entered in
the passwd file.
EXAMPLES
root:TZVtfX5VbS3KY:0:1:System PRIVILEGED Account,,,:/:/bin/sh
adm:*:5:16:Admin Login:/usr/adm:/bin/sh operator:HdgoklKw‐
ZOlvU:25:28:System PRIVILEGED Account,,,:/etc/operator: guest:Nolo‐
gin:-2:-2:anonymous NFS user:/:/bin/date
osfuser:If2eoZ6gmghJo:50002:15:Osf User:/usr/users/osfuser:/bin/csh
marcy:*:201:20:Marcy Swanson,dev,x1234:/usr/users/marcy:/bin/sh
SEE ALSO
Functions: getpwent(3)
Commands: login(1), passwd(1), pwck(8), vipw(8)
Files: prpasswd(4)passwd(4)
