passwd(F)
passwd --
password file
Format
username:[password]:UID:GID:[comment]:directory:[program]
Network Information Service (NIS) entries
+[username]:[password]:::[comment]:[directory]:[program]
+@netgroup:
-username:
-@netgroup:
Description
/etc/passwd is an ASCII file.
Each entry in passwd
occupies one line and describes one user.
Each line contains the
following seven colon-separated fields:
username-
The login name of the user.
password-
Encrypted password.
If this field is null, no password is demanded.
If the
shadow(F)
file exists on the system, then an
``x'' is stored in this field;
the encrypted password and password aging information
are stored in the
shadow
file instead.
UID-
Numerical user ID.
GID-
Numerical group ID as defined in the
group(F)
file.
comment-
This field corresponds to the information displayed as
the output of the finger
command. Refer to
finger(C)
for details of the required format.
directory-
Initial working directory.
program-
Program to use as shell.
If this field is null,
sh
is used by default.
Passwords are encrypted, so passwd has general read
permission and can be used, for example,
to map numerical user IDs to names.
The encrypted password consists of 13 characters chosen
from a 64-character alphabet (., /, 0-9, A-Z, a-z).
In the case that the password is null, the encrypted
password is also null.
Network Information Service (NIS) entries
Entries in passwd beginning with ``+''
incorporate information obtained from NIS.
A ``+::::::'' entry
has the effect of inserting the entire NIS
password file at that point.
If username is
specified after ``+'', the entry for that user is inserted.
Entries for
password, comment, directory, and
program override the corresponding values obtained from
NIS.
If a network group netgroup is specified after ``+@'', all
members of that group are inserted.
Entries beginning with ``-'' exclude users and network groups
from logging in. A ``-username'' entry causes any
subsequent entries in passwd or obtained from NIS
for a user to be ignored.
A ``-@netgroup'' entry causes any subsequent entries for
members of a network group to be ignored.
Password aging
Password aging is in effect for a particular user
if their encrypted password
is followed by a comma and a non-null string
of characters from the above alphabet.
(Such a string must be introduced by root.)
The first character of the age
denotes the maximum number of weeks for which a password is valid.
A user who attempts to log in after their password has expired will be
forced to supply a new one.
The next character
denotes the minimum period in weeks which
must expire before the password may be changed.
The remaining characters define the week
(counted from the beginning of 1970) when the password was
last changed. (A null string is equivalent to zero.)
The first and second characters must have numerical
values in the range 0-63, where the dot (.) is
equal to 0 and lowercase z
is equal to 63.
If the numerical value of both characters is 0,
the user will be forced to change their password the
next time they log in.
If the second character is greater than the first,
only root will be able to change the password.
Examples
An example of a passwd file used in conjunction with
the shadow file:
root:x:0:10:super user:/:/bin/sh
fran:x:121:100:Fran Sisco:/u/fran:/bin/ksh
-renee:
-@marketing:
+diego::::::
+:::::/u/guest:/bin/rksh
+@developers:
root and fran can log in even when the system
is standalone. diego and all members of the network group
developers can log in using their NIS passwords.
developers are restricted to using
rksh
in the directory /u/guest.
renee and all members of the
marketing network group are forbidden to log in.
Files
/etc/passwd-
full pathname of passwd
See also
getprpwent(S),
getpwent(S),
group(F),
login(M),
netgroup(NF),
passwd(C),
pwconv(ADM),
rksh(C),
sh(C),
shadow(F)
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003