{"id":13262,"date":"2019-04-01T10:05:55","date_gmt":"2019-04-01T10:05:55","guid":{"rendered":"http:\/\/www.appservgrid.com\/paw92\/?p=13262"},"modified":"2019-04-01T10:05:55","modified_gmt":"2019-04-01T10:05:55","slug":"the-complete-guide-to-useradd-command-in-linux-15-practical-examples","status":"publish","type":"post","link":"https:\/\/www.appservgrid.com\/paw92\/index.php\/2019\/04\/01\/the-complete-guide-to-useradd-command-in-linux-15-practical-examples\/","title":{"rendered":"The Complete Guide to \u201cuseradd\u201d Command in Linux \u2013 15 Practical Examples"},"content":{"rendered":"

We all are aware about the most popular command called \u2018useradd<\/strong>\u2018 or \u2018adduser<\/strong>\u2018 in Linux. There are times when a Linux System Administrator asked to create user accounts on Linux \u00a0with some specific properties, limitations or comments.<\/p>\n

In Linux, a \u2018useradd<\/strong>\u2018 command is a low-level utility that is used for adding\/creating user accounts in\u00a0Linux<\/strong>\u00a0and other\u00a0Unix-like<\/strong>\u00a0operating systems. The \u2018adduser<\/strong>\u2018 is much similar to\u00a0useradd<\/strong>\u00a0command, because it is just a symbolic link to it.<\/p>\n

\n

\"add<\/a><\/p>\n

useradd command examples<\/p>\n<\/div>\n

In some other Linux distributions,\u00a0useradd<\/strong>\u00a0command may comes with lightly difference version. I suggest you to read your documentation, before using our instructions to create new user accounts in\u00a0Linux<\/strong>.<\/p>\n

When we run \u2018useradd<\/strong>\u2018 command in Linux terminal, it performs following major things:<\/p>\n

    \n
  1. It edits \/etc\/passwd, \/etc\/shadow, \/etc\/group and \/etc\/gshadow files for the newly created User account.<\/li>\n
  2. Creates and populate a home directory for the new user.<\/li>\n
  3. Sets permissions and ownerships to home directory.<\/li>\n<\/ol>\n

    Basic syntax of command is:<\/p>\n

    useradd [options] username<\/pre>\n
    In this article we will show you the most used\u00a015 useradd commands<\/strong>\u00a0with their practical examples in\u00a0Linux<\/strong>. We have divided the section into two parts from\u00a0Basic<\/strong>\u00a0to\u00a0Advance<\/strong>\u00a0usage of command.<\/p>\n
      \n
    1. Part I<\/strong>: Basic usage with\u00a010<\/strong>\u00a0examples<\/li>\n
    2. Part II<\/strong>: Advance usage with\u00a05<\/strong>\u00a0examples<\/li>\n<\/ol>\n
      Part I \u2013\u00a010 Basic Usage of useradd Commands<\/strong><\/div>\n
      1. How to Add a New User in Linux<\/h3>\n
      To add\/create a new user, all you\u2019ve to follow the command \u2018useradd<\/strong>\u2018 or \u2018adduser<\/strong>\u2018 with \u2018username\u2019. The \u2018username\u2019 is a user login name, that is used by user to login into the system.<\/p>\n
      Only one user can be added and that username must be unique (different from other username already exists on the system).<\/p>\n
      For example, to add a new user called \u2018tecmint<\/strong>\u2018, use the following command.<\/p>\n
      [root@tecmint ~]# useradd tecmint<\/pre>\n
      When we add a new user in Linux with \u2018useradd<\/strong>\u2018 command it gets created in locked state and to unlock that user account, we need to set a password for that account with \u2018passwd<\/strong>\u2018 command.<\/p>\n
      [root@tecmint ~]# passwd tecmint\r\nChanging password for user tecmint.\r\nNew UNIX password:\r\nRetype new UNIX password:\r\npasswd: all authentication tokens updated successfully.<\/pre>\n
      Once a new user created, it\u2019s entry automatically added to the \u2018\/etc\/passwd<\/strong>\u2018 file. The file is used to store users information and the entry should be.<\/p>\n
      tecmint:x:504:504:tecmint:\/home\/tecmint:\/bin\/bash<\/pre>\n
      The above entry contains a set of seven colon-separated fields, each field has it\u2019s own meaning. Let\u2019s see what are these fields:<\/p>\n
        \n
      1. Username<\/strong>: User login name used to login into system. It should be between 1 to 32 charcters long.<\/li>\n
      2. Password<\/strong>: User password (or x character) stored in \/etc\/shadow file in encrypted format.<\/li>\n
      3. User ID (UID)<\/strong>: Every user must have a User ID (UID) User Identification Number. By default UID 0 is reserved for root user and UID\u2019s ranging from 1-99 are reserved for other predefined accounts. Further UID\u2019s ranging from 100-999 are reserved for system accounts and groups.<\/li>\n
      4. Group ID (GID)<\/strong>: The primary Group ID (GID) Group Identification Number stored in \/etc\/group file.<\/li>\n
      5. User Info<\/strong>: This field is optional and allow you to define extra information about the user. For example, user full name. This field is filled by \u2018finger\u2019 command.<\/li>\n
      6. Home Directory<\/strong>: The absolute location of user\u2019s home directory.<\/li>\n
      7. Shell<\/strong>: The absolute location of a user\u2019s shell i.e. \/bin\/bash.<\/li>\n<\/ol>\n
        2. Create a User with Different Home Directory<\/h3>\n
        By default \u2018useradd<\/strong>\u2018 command creates a user\u2019s home directory under\u00a0\/home<\/strong>\u00a0directory with username. Thus, for example, we\u2019ve seen above the default home directory for the user \u2018tecmint<\/strong>\u2018 is \u2018\/home\/tecmint<\/strong>\u2018.<\/p>\n
        However, this action can be changed by using \u2018-d<\/strong>\u2018 option along with the location of new home directory (i.e.\/data\/projects<\/strong>). For example, the following command will create a user \u2018anusha<\/strong>\u2018 with a home directory \u2018\/data\/projects<\/strong>\u2018.<\/p>\n
        [root@tecmint ~]# useradd -d \/data\/projects anusha<\/pre>\n
        You can see the user home directory and other user related information like user id, group id, shell and comments.<\/p>\n
        [root@tecmint ~]# cat \/etc\/passwd | grep anusha\r\n\r\nanusha<\/strong>:x:505:505::\/data\/projects<\/strong>:\/bin\/bash<\/pre>\n
        3. Create a User with Specific User ID<\/h3>\n
        In Linux, every user has its own\u00a0UID<\/strong>\u00a0(Unique Identification Number<\/strong>). By default, whenever we create a new user accounts in\u00a0Linux<\/strong>, it assigns userid\u00a0500<\/strong>,\u00a0501<\/strong>,\u00a0502<\/strong>\u00a0and so on\u2026<\/p>\n
        But, we can create user\u2019s with custom userid with \u2018-u<\/strong>\u2018 option. For example, the following command will create a user \u2018navin<\/strong>\u2018 with custom userid \u2018999<\/strong>\u2018.<\/p>\n
        [root@tecmint ~]# useradd -u 999 navin<\/pre>\n
        Now, let\u2019s verify that the user created with a defined userid (999<\/strong>) using following command.<\/p>\n
        [root@tecmint ~]# cat \/etc\/passwd | grep tecmint\r\n\r\nnavin:x:999<\/strong>:999::\/home\/tecmint:\/bin\/bash<\/pre>\n
        NOTE<\/strong>: Make sure the value of a user ID must be unique from any other already created users on the system.<\/p>\n
        4. Create a User with Specific Group ID<\/h3>\n
        Similarly, every user has its own\u00a0GID<\/strong>\u00a0(Group Identification Number<\/strong>). We can create users with specific group ID\u2019s as well with\u00a0-g<\/strong>\u00a0option.<\/p>\n
        Here in this example, we will add a user \u2018tarunika<\/strong>\u2018 with a specific\u00a0UID<\/strong>\u00a0and\u00a0GID<\/strong>\u00a0simultaneously with the help of \u2018-u<\/strong>\u2018 and \u2018-g<\/strong>\u2018 options.<\/p>\n
        [root@tecmint ~]# useradd -u 1000 -g 500 tarunika<\/pre>\n
        Now, see the assigned user id and group id in \u2018\/etc\/passwd<\/strong>\u2018 file.<\/p>\n
        [root@tecmint ~]# cat \/etc\/passwd | grep tarunika\r\n\r\ntarunika<\/strong>:x:1000<\/strong>:500<\/strong>::\/home\/tarunika:\/bin\/bash<\/pre>\n
        5. Add a User to Multiple Groups<\/h3>\n
        The \u2018-G<\/strong>\u2018 option is used to add a user to additional groups. Each group name is separated by a comma, with no intervening spaces.<\/p>\n
        Here in this example, we are adding a user \u2018tecmint<\/strong>\u2018 into multiple groups like\u00a0admins<\/strong>,\u00a0webadmin<\/strong>\u00a0and\u00a0developer<\/strong>.<\/p>\n
        [root@tecmint ~]# useradd -G admins,webadmin,developers tecmint<\/pre>\n
        Next, verify that the multiple groups assigned to the user with id command.<\/p>\n
        [root@tecmint ~]# id tecmint\r\n\r\nuid=1001(tecmint) gid=1001(tecmint)\r\ngroups=1001(tecmint<\/strong>),500(admins<\/strong>),501(webadmin<\/strong>),502(developers<\/strong>)\r\ncontext=root:system_r:unconfined_t:SystemLow-SystemHigh<\/pre>\n
        6. Add a User without Home Directory<\/h3>\n
        In some situations, where we don\u2019t want to assign a home directories for a user\u2019s, due to some security reasons. In such situation, when a user logs into a system that has just restarted, its home directory will be root. When such user uses\u00a0su command<\/a>, its login directory will be the previous user home directory.<\/p>\n
        To create user\u2019s without their home directories, \u2018-M<\/strong>\u2018 is used. For example, the following command will create a user \u2018shilpi<\/strong>\u2018 without a home directory.<\/p>\n
        [root@tecmint ~]# useradd -M shilpi<\/pre>\n
        Now, let\u2019s verify that the user is created without home directory, using ls command.<\/p>\n
        [root@tecmint ~]# ls -l \/home\/shilpi\r\n\r\nls: cannot access \/home\/shilpi<\/strong>: No such file or directory<\/pre>\n
        7. Create a User with Account Expiry Date<\/h3>\n
        By default, when we add user\u2019s with \u2018useradd<\/strong>\u2018 command user account never get expires i.e their expiry date is set to\u00a00<\/strong>\u00a0(means never expired).<\/p>\n
        However, we can set the expiry date using \u2018-e<\/strong>\u2018 option, that sets date in\u00a0YYYY-MM-DD<\/strong>\u00a0format. This is helpful for creating temporary accounts for a specific period of time.<\/p>\n
        Here in this example, we create a user \u2018aparna<\/strong>\u2018 with account expiry date i.e.\u00a027th April 2014<\/strong>\u00a0in\u00a0YYYY-MM-DD<\/strong>format.<\/p>\n
        [root@tecmint ~]# useradd -e 2014-03-27 aparna<\/pre>\n
        Next, verify the age of account and password with \u2018chage<\/strong>\u2018 command for user \u2018aparna<\/strong>\u2018 after setting account expiry date.<\/p>\n
        [root@tecmint ~]# chage -l aparna\r\n\r\nLast password change\t\t\t\t\t\t: Mar 28, 2014\r\nPassword expires\t\t\t\t\t\t: never\r\nPassword inactive\t\t\t\t\t\t: never\r\nAccount expires\t\t\t\t\t\t\t: Mar 27, 2014\r\nMinimum number of days between password change\t\t        : 0\r\nMaximum number of days between password change\t\t        : 99999\r\nNumber of days of warning before password expires\t\t: 7<\/pre>\n
        8. Create a User with Password Expiry Date<\/h3>\n
        The \u2018-f<\/strong>\u2018 argument is used to define the number of days after a password expires. A value of\u00a00<\/strong>\u00a0inactive the user account as soon as the password has expired. By default, the password expiry value set to\u00a0-1<\/strong>\u00a0means never expire.<\/p>\n
        Here in this example, we will set a account password expiry date i.e.\u00a045 days<\/strong>\u00a0on a user \u2018tecmint\u2019 using \u2018-e<\/strong>\u2018 and \u2018-f<\/strong>\u2018 options.<\/p>\n
        [root@tecmint ~]# useradd -e 2014-04-27 -f 45 tecmint<\/pre>\n
        9. Add a User with Custom Comments<\/h3>\n
        The \u2018-c<\/strong>\u2018 option allows you to add custom comments, such as user\u2019s\u00a0full name<\/strong>,\u00a0phone number<\/strong>, etc to\u00a0\/etc\/passwd<\/strong>\u00a0file. The comment can be added as a single line without any spaces.<\/p>\n
        For example, the following command will add a user \u2018mansi<\/strong>\u2018 and would insert that user\u2019s full name,\u00a0Manis Khurana<\/strong>, into the comment field.<\/p>\n
        [root@tecmint ~]# useradd -c \"Manis Khurana\" mansi<\/pre>\n
        You can see your comments in \u2018\/etc\/passwd<\/strong>\u2018 file in comments section.<\/p>\n
        [root@tecmint ~]# tail -1 \/etc\/passwd\r\n\r\nmansi<\/strong>:x:1006:1008:Manis Khurana<\/strong>:\/home\/mansi:\/bin\/sh<\/pre>\n
        10. Change User Login Shell:<\/h3>\n
        Sometimes, we add users which has nothing to do with login shell or sometimes we require to assign different shells to our users. We can assign different login shells to a each user with \u2018-s<\/strong>\u2018 option.<\/p>\n
        Here in this example, will add a user \u2018tecmint<\/strong>\u2018 without login shell i.e. \u2018\/sbin\/nologin<\/strong>\u2018 shell.<\/p>\n
        [root@tecmint ~]# useradd -s \/sbin\/nologin tecmint<\/pre>\n
        You can check assigned shell to the user in \u2018\/etc\/passwd<\/strong>\u2018 file.<\/p>\n
        [root@tecmint ~]# tail -1 \/etc\/passwd\r\n\r\ntecmint<\/strong>:x:1002:1002::\/home\/tecmint:\/sbin\/nologin\r\n<\/strong><\/pre>\n
        Part II \u2013\u00a05 Advance Usage of useradd Commands<\/strong><\/div>\n
        11. Add a User with Specific Home Directory, Default Shell and Custom Comment<\/h3>\n
        The following command will create a user \u2018ravi<\/strong>\u2018 with home directory \u2018\/var\/www\/tecmint<\/strong>\u2018, default shell\u00a0\/bin\/bash<\/strong>and adds extra information about user.<\/p>\n
        [root@tecmint ~]# useradd -m -d \/var\/www\/ravi -s \/bin\/bash -c \"TecMint Owner\" -U ravi<\/pre>\n
        In the above command \u2018-m -d<\/strong>\u2018 option creates a user with specified home directory and the \u2018-s<\/strong>\u2018 option set the user\u2019s default shell i.e.\u00a0\/bin\/bash<\/strong>. The \u2018-c<\/strong>\u2018 option adds the extra information about user and \u2018-U<\/strong>\u2018 argument create\/adds a group with the same name as the user.<\/p>\n
        12. Add a User with Home Directory, Custom Shell, Custom Comment and UID\/GID<\/h3>\n
        The command is very similar to above, but here we defining shell as \u2018\/bin\/zsh<\/strong>\u2018 and custom\u00a0UID<\/strong>\u00a0and\u00a0GID<\/strong>\u00a0to a user \u2018tarunika<\/strong>\u2018. Where \u2018-u<\/strong>\u2018 defines new user\u2019s\u00a0UID<\/strong>\u00a0(i.e.\u00a01000<\/strong>) and whereas \u2018-g<\/strong>\u2018 defines\u00a0GID<\/strong>\u00a0(i.e.\u00a01000<\/strong>).<\/p>\n
        [root@tecmint ~]# useradd -m -d \/var\/www\/tarunika -s \/bin\/zsh -c \"TecMint Technical Writer\" -u 1000 -g 1000 tarunika<\/pre>\n
        13. Add a User with Home Directory, No Shell, Custom Comment and User ID<\/h3>\n
        The following command is very much similar to above two commands, the only difference is here, that we disabling login shell to a user called \u2018avishek<\/strong>\u2018 with custom\u00a0User ID<\/strong>\u00a0(i.e.\u00a01019<\/strong>).<\/p>\n
        Here \u2018-s<\/strong>\u2018 option adds the default shell\u00a0\/bin\/bash<\/strong>, but in this case we set login to \u2018\/usr\/sbin\/nologin<\/strong>\u2018. That means user \u2018avishek<\/strong>\u2018 will not able to login into the system.<\/p>\n
        [root@tecmint ~]# useradd -m -d \/var\/www\/avishek -s \/usr\/sbin\/nologin -c \"TecMint Sr. Technical Writer\" -u 1019 avishek<\/pre>\n
        14. Add a User with Home Directory, Shell, Custom Skell\/Comment and User ID<\/h3>\n
        The only change in this command is, we used \u2018-k<\/strong>\u2018 option to set custom skeleton directory i.e.\u00a0\/etc\/custom.skell<\/strong>, not the default one\u00a0\/etc\/skel<\/strong>. We also used \u2018-s<\/strong>\u2018 option to define different shell i.e.\u00a0\/bin\/tcsh<\/strong>\u00a0to user \u2018navin<\/strong>\u2018.<\/p>\n
        [root@tecmint ~]# useradd -m -d \/var\/www\/navin -k \/etc\/custom.skell -s \/bin\/tcsh -c \"No Active Member of TecMint\" -u 1027 navin<\/pre>\n
        15. Add a User without Home Directory, No Shell, No Group and Custom Comment<\/h3>\n
        This following command is very different than the other commands explained above. Here we used \u2018-M<\/strong>\u2018 option to create user without user\u2019s home directory and \u2018-N<\/strong>\u2018 argument is used that tells the system to only create username (without group). The \u2018-r<\/strong>\u2018 arguments is for creating a system user.<\/p>\n
        [root@tecmint ~]# useradd -M -N -r -s \/bin\/false -c \"Disabled TecMint Member\" clayton<\/pre>\n
        For more information and options about useradd, run \u2018useradd<\/strong>\u2018 command on the terminal to see available options.<\/p>\n
        Read Also<\/b>:\u00a015 usermod Command Examples<\/a><\/p>\n
        Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
        We all are aware about the most popular command called \u2018useradd\u2018 or \u2018adduser\u2018 in Linux. There are times when a Linux System Administrator asked to create user accounts on Linux \u00a0with some specific properties, limitations or comments. In Linux, a \u2018useradd\u2018 command is a low-level utility that is used for adding\/creating user accounts in\u00a0Linux\u00a0and other\u00a0Unix-like\u00a0operating … <\/p>\n
        Continue reading “The Complete Guide to \u201cuseradd\u201d Command in Linux \u2013 15 Practical Examples”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-13262","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/13262","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/comments?post=13262"}],"version-history":[{"count":1,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/13262\/revisions"}],"predecessor-version":[{"id":13263,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/13262\/revisions\/13263"}],"wp:attachment":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/media?parent=13262"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/categories?post=13262"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/tags?post=13262"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}