passwd(1) USER COMMANDS passwd(1)
NAME
passwd - change login password and password attributes
SYNOPSIS
passwd [ name ]
passwd [ -l | -d ] [ -f ] [ -n min ] [ -x max ] [ -w warn ]
name
passwd -s [ -a ]
passwd -s [ name ]
DESCRIPTION
The passwd command changes the password or lists password
attributes associated with the user's login name. Addition-
ally, privileged-users may use passwd to install or change
passwords and attributes associated with any login name.
When used to change a password, passwd prompts ordinary
users for their old password, if any. It then prompts for
the new password twice. When the old password is entered,
passwd checks to see if it has "aged" sufficiently. If
"aging" is insufficient, passwd terminates; see shadow(4).
Assuming aging is sufficient, a check is made to ensure that
the new password meets construction requirements. When the
new password is entered a second time, the two copies of the
new password are compared. If the two copies are not ident-
ical the cycle of prompting for the new password is repeated
for at most two more times. Passwords must be constructed
to meet the following requirements:
Each password must have at least six characters. Only
the first eight characters are significant. PASSLEN is
found in /etc/default/passwd and is set to 6. Each
password must contain at least two alphabetic charac-
ters and at least one numeric or special character. In
this case, "alphabetic" refers to all upper or lower
case letters. Each password must differ from the
user's login name and any reverse or circular shift of
that login name. For comparison purposes, an upper
case letter and its corresponding lower case letter are
equivalent. New passwords must differ from the old by
at least three characters. For comparison purposes, an
upper case letter and its corresponding lower case
letter are equivalent.
Super-users (e.g., real and effective uid equal to zero, see
id(1M) and su(1M)) may change any password; hence, passwd
does not prompt privileged-users for the old password.
Privileged-users are not forced to comply with password
aging and password construction requirements. A
privileged-user can create a null password by entering a
carriage return in response to the prompt for a new
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passwd(1) USER COMMANDS passwd(1)
password. (This differs from passwd -d because the "pass-
word" prompt will still be displayed.) Any user may use the
-s option to show password attributes for his or her own
login name. The format of the display will be:
name status mm/dd/yy min max warn
or, if password aging information is not present,
name status
where
name The login ID of the user.
status The password status of name: "PS" stands for
passworded or locked, "LK" stands for locked,
and "NP" stands for no password.
mm/dd/yy The date password was last changed for name.
(Note that all password aging dates are deter-
mined using Greenwich Mean Time and, therefore,
may differ by as much as a day in other time
zones.)
min The minimum number of days required between
password changes for name. MINWEEKS is found in
/etc/default/passwd and is set to NULL.
max The maximum number of days the password is valid
for name. MAXWEEKS is found in
/etc/default/passwd and is set to NULL.
warn The number of days relative to max before the
password expires that the name will be warned.
Only a privileged-user can use the following
options:
-l Locks password entry for name.
-d Deletes password for name. The login name will
not be prompted for password.
-n Set minimum field for name. The min field con-
tains the minimum number of days between password
changes for name. If min is greater than max, the
user may not change the password. Always use this
option with the -x option, unless max is set to -1
(aging turned off). In that case, min need not be
set.
-x Set maximum field for name. The max field con-
tains the number of days that the password is
valid for name. The aging for name will be turned
off immediately if max is set to -1. If it is set
to 0, then the user is forced to change the
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passwd(1) USER COMMANDS passwd(1)
password at the next login session and aging is
turned off.
-w Set warn field for name. The warn field contains
the number of days before the password expires
that the user will be warned.
-a Show password attributes for all entries. Use
only with -s option; name must not be provided.
-f Force the user to change password at the next
login by expiring the password for name.
FILES
/etc/shadow, /etc/passwd, /etc/oshadow
SEE ALSO
login(1).
crypt(3C), passwd(4), shadow(4) in the Programmer's Refer-
ence Manual.
useradd(1M), usermod(1M), userdel(1M), id(1M), passmgmt(1M),
pwconv(1M), su(1M), in the System Administrator's Reference
Manual.
DIAGNOSTICS
The passwd command exits with one of the following values:
0 SUCCESS.
1 Permission denied.
2 Invalid combination of options.
3 Unexpected failure. Password file unchanged.
4 Unexpected failure. Password file(s) missing.
5 Password file(s) busy. Try again later.
6 Invalid argument to option.
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