12.1.1 Registration

12.1.1.1 Password file - /etc/passwd

login-id:password:user-id#:group-id#:User Info:home-dir:shell

where these fields represent:

• login-id 2-->8 characters containing lower case alphabetic characters and numbers.

• password encrypted password, 13 characters, of which the first 2 are the salt. If this field is empty login does NOT prompt for a password. If this field contains 1-->12 characters NO password will ever match.

• user-id# uid, numerical ID for the user, should be between 0 and 60000 (SunOS 4.1.X, Solaris 2.0-2.5). Solaris 2.5.1 uses a signed long for this value, MAXUID in /usr/include/sys/param.h, raising the limit to 231.

• group-id# gid, numerical ID for the group that the user belongs to, should be between 0 and 60000.

• User Info User's real name, etc.

• home-dir Path to the directory the user is logged in to.

• shell The user's initial shell program. The default shell if this is empty is /usr/bin/sh.

sysdiag:*:0:1:System Diagnostic:/usr/diag/sysdiag:/usr/diag/sysdiag/sysdiag

frank:yPf3M5qMgglUc:101:10:Frank G Fiamingo:/home/tardis/frank:/usr/bin/csh

The home directory, field 6 of /etc/passwd, specifies the location of the user's home within the operating system. The user is placed here by the login program. For a normal login user this directory should be owned by the user.

The shell, field 7 of /etc/passwd, is the program run when the user logs in. Generally this is a shell that acts as a command interpreter, reading from a terminal and translating the commands into system actions, e.g. sh (Bourne shell), csh (C shell), or tcsh (extended C shell). Occasionally this is not a shell, but a stand-alone program, as in the sysdiag passwd entry given above. Here when you login as "sysdiag" you go directly into the systems diagnostics program.

For SunOS 4.1.X you would generally edit the passwd file using the vipw command. This saves a copy of passwd as ptmp, uses the vi editor by default (or the editor set by your VISUAL or EDITOR environment variable), and verifies the consistency of the root entry before writing the file back to passwd. The shell for the root account must be listed in /etc/shells, if the file exists. The ptmp file also serves as a lock against a simultaneous use of vipw.