passwd(4) [osf1 man page]
passwd(4) Kernel Interfaces Manual passwd(4) NAME
passwd - 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 information 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 password 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 command to edit password entries. This ensures that the hashed password database is rebuilt. 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 follows: 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:HdgoklKwZOlvU:25:28:System PRIVILEGED Account,,,:/etc/operator: guest:Nologin:-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 RELATED INFORMATION
Functions: getpwent(3) Commands: login(1), passwd(1), pwck(8), vipw(8) Files: prpasswd(4) delim off passwd(4)
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PASSWD(5) BSD File Formats Manual PASSWD(5) NAME
passwd, master.passwd -- format of the password file DESCRIPTION
The /etc/passwd file is a legacy BSD 4.3 format file. It is mostly unused, but is updated by some utility programs. Its format is similar to the /etc/master.passwd file, except that it does not contain the class, change, and expire fields described below. The /etc/master.passwd file comprises newline separated records, one per user. Each line contains ten colon (``:'') separated fields. These fields are as follows: name User's login name. password User's encrypted password. uid User's id. gid User's login group id. class User's general classification (unused). change Password change time. expire Account expiration time. gecos User's full name. home_dir User's home directory. shell 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 id's, it is usually a mistake to do so. Rou- tines 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 upper-case 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 password field is empty, no password will be required to gain access to the machine. This is almost invariably a mistake. Because these files contain the encrypted user passwords, they should not be readable by any- one without appropriate privileges. The group field is the group that the user will be placed in upon login. Since this system supports multiple groups (see groups(1)) this field currently has little special meaning. The class field is currently unused. The change field is the number in seconds, GMT, from the epoch, until the password for the account must be changed. This field may be left empty to turn off the password aging feature. The expire field is the number in seconds, GMT, from the epoch, until the account expires. This field may be left empty to turn off the account aging feature. The gecos field normally contains the user's full name. Note that Mac OS X differs from some other operating systems, where the gecos field may contain other comma-separcted information about the user. The home_dir field is the user's home directory. This is the full path name where the user will be placed on login. The shell field is the command interpreter the user prefers. If there is nothing in the shell field, the Bourne shell (/bin/sh) is assumed. INTERACTION WITH DIRECTORY SERVICES
Processes generally find user records using one of the getpwent(3) family of functions. On Mac OS X, these functions interact with the DirectoryService(8) daemon, which reads the /etc/master.passwd file as well as searching other directory information services to find user accounts. FILES
/etc/passwd /etc/master.passwd SEE ALSO
chpass(1), login(1), passwd(1), getpwent(3), netgroup(5), DirectoryService(8), pwd_mkdb(8), vipw(8) HISTORY
A passwd file format appeared in Version 6 AT&T UNIX. BSD
July 18, 1995 BSD