linux command

usermod

Linux Command – usermod ใช้ในการเปลี่ยนแปลงข้อมูลของ user

 

คำสั่ง

usermod -d <user homepath> <username>

$ usermod -d /home/exampleusernew exampleuser

 

โครงสร้างคำสั่ง

 usermod [options] LOGIN

 

รายละเอียด

เป็นคำสั่งที่ใช้ในการเปลี่ยนแปลงข้อมูลของ user

 

Option

 -a, --append
 Add the user to the supplementary group(s). Use only with the -G option.

 -c, --comment COMMENT
 The new value of the user's password file comment field. It is normally modified using the chfn(1) utility.

 -d, --home HOME_DIR
 The user's new login directory.

 If the -m option is given, the contents of the current home directory will be moved to the new home directory, which is created if it does not already exist.

 -e, --expiredate EXPIRE_DATE
 The date on which the user account will be disabled. The date is specified in the format YYYY-MM-DD.

 An empty EXPIRE_DATE argument will disable the expiration of the account.

 This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none.

 -f, --inactive INACTIVE
 The number of days after a password expires until the account is permanently disabled.

 A value of 0 disables the account as soon as the password has expired, and a value of -1 disables the feature.

 This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none.

 -g, --gid GROUP
 The group name or number of the user's new initial login group. The group must exist.

 Any file from the user's home directory owned by the previous primary group of the user will be owned by this new group.

 The group ownership of files outside of the user's home directory must be fixed manually.

 -G, --groups GROUP1[,GROUP2,...[,GROUPN]]]
 A list of supplementary groups which the user is also a member of. Each group is separated from the next by a comma, with no intervening whitespace. The groups are subject to
 the same restrictions as the group given with the -g option.

 If the user is currently a member of a group which is not listed, the user will be removed from the group. This behaviour can be changed via the -a option, which appends the
 user to the current supplementary group list.

 -l, --login NEW_LOGIN
 The name of the user will be changed from LOGIN to NEW_LOGIN. Nothing else is changed. In particular, the user's home directory or mail spool should probably be renamed
 manually to reflect the new login name.

 -L, --lock
 Lock a user's password. This puts a '!' in front of the encrypted password, effectively disabling the password. You can't use this option with -p or -U.

 Note: if you wish to lock the account (not only access with a password), you should also set the EXPIRE_DATE to 1.

 -m, --move-home
 Move the content of the user's home directory to the new location.

 This option is only valid in combination with the -d (or --home) option.

 usermod will try to adapt the ownership of the files and to copy the modes, ACL and extended attributes, but manual changes might be needed afterwards.

 -o, --non-unique
 When used with the -u option, this option allows to change the user ID to a non-unique value.

 -p, --password PASSWORD
 The encrypted password, as returned by crypt(3).

 Note: This option is not recommended because the password (or encrypted password) will be visible by users listing the processes.

 The password will be written in the local /etc/passwd or /etc/shadow file. This might differ from the password database configured in your PAM configuration.

 You should make sure the password respects the system's password policy.

 -R, --root CHROOT_DIR
 Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.

 -s, --shell SHELL
 The name of the user's new login shell. Setting this field to blank causes the system to select the default login shell.

 -u, --uid UID
 The new numerical value of the user's ID.

 This value must be unique, unless the -o option is used. The value must be non-negative.

 The user's mailbox, and any files which the user owns and which are located in the user's home directory will have the file user ID changed automatically.

 The ownership of files outside of the user's home directory must be fixed manually.

 No checks will be performed with regard to the UID_MIN, UID_MAX, SYS_UID_MIN, or SYS_UID_MAX from /etc/login.defs.

 -U, --unlock
 Unlock a user's password. This removes the '!' in front of the encrypted password. You can't use this option with -p or -L.

 Note: if you wish to unlock the account (not only access with a password), you should also set the EXPIRE_DATE (for example to 99999, or to the EXPIRE value from
 /etc/default/useradd).

 -v, --add-sub-uids FIRST-LAST
 Add a range of subordinate uids to the user's account.

 This option may be specified multiple times to add multiple ranges to a users account.

 No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from /etc/login.defs.

 -V, --del-sub-uids FIRST-LAST
 Remove a range of subordinate uids from the user's account.

 This option may be specified multiple times to remove multiple ranges to a users account. When both --del-sub-uids and --add-sub-uids are specified, the removal of all
 subordinate uid ranges happens before any subordinate uid range is added.

 No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from /etc/login.defs.

 -w, --add-sub-gids FIRST-LAST
 Add a range of subordinate gids to the user's account.

 This option may be specified multiple times to add multiple ranges to a users account.

 No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from /etc/login.defs.

 -W, --del-sub-gids FIRST-LAST
 Remove a range of subordinate gids from the user's account.

 This option may be specified multiple times to remove multiple ranges to a users account. When both --del-sub-gids and --add-sub-gids are specified, the removal of all
 subordinate gid ranges happens before any subordinate gid range is added.

 No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from /etc/login.defs.

 -Z, --selinux-user SEUSER
 The new SELinux user for the user's login.

 A blank SEUSER will remove the SELinux user mapping for user LOGIN (if any).

 

กลุ่มคำสั่ง

adduser, chfn(1), chsh(1), passwd(1), crypt(3), gpasswd(8), groupadd(8), groupdel(8), groupmod(8), login.defs(5), subgid(5), subuid(5), useradd(8), userdel(8).

 

Reference:

คำสั่ง Unix – Linux Command

Linux, Unix

 

Author: Suphakit Annoppornchai

Credit: https://saixiii.com

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