Both the passwd and usermod command can be used to lock or unlock a user account as well as modifying password ageing information for the account. The chage command however is only able to modify password ageing information, but does have the ability to expire a user account.
chage
Only has the capability to modify a user accounts password expiry information.
[root@server1 ~]# chage -h
Usage: chage [options] LOGIN
Options:
-d, --lastday LAST_DAY set date of last password change to LAST_DAY
-E, --expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE
-h, --help display this help message and exit
-I, --inactive INACTIVE set password inactive after expiration
to INACTIVE
-l, --list show account aging information
-m, --mindays MIN_DAYS set minimum number of days before password
change to MIN_DAYS
-M, --maxdays MAX_DAYS set maximum number of days before password
change to MAX_DAYS
-R, --root CHROOT_DIR directory to chroot into
-W, --warndays WARN_DAYS set expiration warning days to WARN_DAYS
passwd
The passwd command is used to set or modify a users password in addition to being able to modify user account attributes and lock or unlock a users account.
Locking an account will add an “!” to the beginning of the password field in /etc/shadow the corresponding unlock flag will remove this “!” from the field.
Locking a user account with the passwd command is accomplished with the -l flag:
[root@server1 ~]# passwd -l user10 Locking password for user user10. passwd: Success [root@server1 ~]# grep user10 /etc/shadow user10:!!$6$xpkPmLMWCP5NFp/h$VYfghUJGyeRt64nQFaTLNLctrryrawaMeEBc99SpsjJv0U6rr3.nLyDNfbbegB3DtIylnnB1dH.RqQ6IAJHT7.:18743:0:99999:7:::
Unlocking a user account with passwd command with the -u flag, shown below:
[root@server1 ~]# passwd -u user10 Unlocking password for user user10. passwd: Success [root@server1 ~]# grep user10 /etc/shadow user10:$6$xpkPmLMWCP5NFp/h$VYfghUJGyeRt64nQFaTLNLctrryrawaMeEBc99SpsjJv0U6rr3.nLyDNfbbegB3DtIylnnB1dH.RqQ6IAJHT7.:18743:0:99999:7:::
Further usefule information is found in the man files or with the help command:
[root@server1 ~]# passwd --help
Usage: passwd [OPTION...] <accountName>
-k, --keep-tokens keep non-expired authentication tokens
-d, --delete delete the password for the named account (root only); also removes password lock if any
-l, --lock lock the password for the named account (root only)
-u, --unlock unlock the password for the named account (root only)
-e, --expire expire the password for the named account (root only)
-f, --force force operation
-x, --maximum=DAYS maximum password lifetime (root only)
-n, --minimum=DAYS minimum password lifetime (root only)
-w, --warning=DAYS number of days warning users receives before password expiration (root only)
-i, --inactive=DAYS number of days after password expiration when an account becomes disabled (root only)
-S, --status report password status on the named account (root only)
--stdin read new tokens from stdin (root only)
Help options:
-?, --help Show this help message
--usage Display brief usage message
usermod
The usermod command is for modifying user account attributes but it may also be used to lock or unlock the user account by using the flags -L and -U respectively as seen below:
Locking a user account with the usermod command:
[root@server1 ~]# usermod -L user10 [root@server1 ~]# grep user10 /etc/shadow user10:!$6$xpkPmLMWCP5NFp/h$VYfghUJGyeRt64nQFaTLNLctrryrawaMeEBc99SpsjJv0U6rr3.nLyDNfbbegB3DtIylnnB1dH.RqQ6IAJHT7.:18743:0:99999:7:::
usermod can unlock an account with the -U flag:
[root@server1 ~]# usermod -U user10 [root@server1 ~]# grep user10 /etc/shadow user10:$6$xpkPmLMWCP5NFp/h$VYfghUJGyeRt64nQFaTLNLctrryrawaMeEBc99SpsjJv0U6rr3.nLyDNfbbegB3DtIylnnB1dH.RqQ6IAJHT7.:18743:0:99999:7:::
More flags are available for the usermod command and can be discovered via the man pages or with the help command:
[root@server1 ~]# usermod --help
Usage: usermod [options] LOGIN
Options:
-c, --comment COMMENT new value of the GECOS field
-d, --home HOME_DIR new home directory for the user account
-e, --expiredate EXPIRE_DATE set account expiration date to EXPIRE_DATE
-f, --inactive INACTIVE set password inactive after expiration
to INACTIVE
-g, --gid GROUP force use GROUP as new primary group
-G, --groups GROUPS new list of supplementary GROUPS
-a, --append append the user to the supplemental GROUPS
mentioned by the -G option without removing
the user from other groups
-h, --help display this help message and exit
-l, --login NEW_LOGIN new value of the login name
-L, --lock lock the user account
-m, --move-home move contents of the home directory to the
new location (use only with -d)
-o, --non-unique allow using duplicate (non-unique) UID
-p, --password PASSWORD use encrypted password for the new password
-R, --root CHROOT_DIR directory to chroot into
-P, --prefix PREFIX_DIR prefix directory where are located the /etc/* files
-s, --shell SHELL new login shell for the user account
-u, --uid UID new UID for the user account
-U, --unlock unlock the user account
-v, --add-subuids FIRST-LAST add range of subordinate uids
-V, --del-subuids FIRST-LAST remove range of subordinate uids
-w, --add-subgids FIRST-LAST add range of subordinate gids
-W, --del-subgids FIRST-LAST remove range of subordinate gids
-Z, --selinux-user SEUSER new SELinux user mapping for the user account
by 