newusers - update and create new users in batch
newusers [options] [file]
The newusers command reads a file (or the standard input by default) and uses this information to update a set of existing users or to create new users. Each line is in the same format as the standard password file (see passwd(5)) with the exceptions explained below: pw_name:pw_passwd:pw_uid:pw_gid:pw_gecos:pw_dir:pw_shell pw_name This is the name of the user. It can be the name of a new user or the name of an existing user (or an user created before by newusers). In case of an existing user, the user's information will be changed, otherwise a new user will be created. pw_passwd This field will be encrypted and used as the new value of the encrypted password. pw_uid This field is used to define the UID of the user. If the field is empty, an new (unused) UID will be defined automatically by newusers. If this field contains a number, this number will be used as the UID. If this field contains the name of an existing user (or the name of an user created before by newusers), the UID of the specified user will be used. If the UID of an existing user is changed, the files ownership of the user's file should be fixed manually. pw_gid This field is used to define the primary group ID for the user. If this field contains the name of an existing group (or a group created before by newusers), the GID of this group will be used as the primary group ID for the user. If this field is a number, this number will be used as the primary group ID of the user. If no groups exist with this GID, a new group will be created with this GID, and the name of the user. If this field is empty, a new group will be created with the name of the user and a GID will be automatically defined by newusers to be used as the primary group ID for the user and as the GID for the new group. If this field contains the name of a group which does not exist (and was not created before by newusers), a new group will be created with the specified name and a GID will be automatically defined by newusers to be used as the primary group ID for the user and GID for the new group. pw_gecos This field is copied in the GECOS field of the user. pw_dir This field is used to define the home directory of the user. If this field does not specify an existing directory, the specified directory is created, with ownership set to the user being created or updated and its primary group. If the home directory of an existing user is changed, newusers does not move or copy the content of the old directory to the new location. This should be done manually. pw_shell This field defines the shell of the user. No checks are performed on this field. newusers first tries to create or change all the specified users, and then write these changes to the user or group databases. If an error occurs (except in the final writes to the databases), no changes are committed to the databases. During this first pass, users are created with a locked password (and passwords are not changed for the users which are not created). A second pass is used to update the passwords using PAM. Failures to update a password are reported, but will not stop the other password updates. This command is intended to be used in a large system environment where many accounts are updated at a single time.
The options which apply to the newusers command are: -h, --help Display help message and exit. -r, --system Create a system account. System users will be created with no aging information in /etc/shadow, and their numeric identifiers are chosen in the SYS_UID_MIN-SYS_UID_MAX range, defined in login.defs, instead of UID_MIN-UID_MAX (and their GID counterparts for the creation of groups). -R, --root CHROOT_DIR Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory.
The input file must be protected since it contains unencrypted passwords.
The following configuration variables in /etc/login.defs change the behavior of this tool: GID_MAX (number), GID_MIN (number) Range of group IDs used for the creation of regular groups by useradd, groupadd, or newusers. The default value for GID_MIN (resp. GID_MAX) is 1000 (resp. 60000). MAX_MEMBERS_PER_GROUP (number) Maximum members per group entry. When the maximum is reached, a new group entry (line) is started in /etc/group (with the same name, same password, and same GID). The default value is 0, meaning that there are no limits in the number of members in a group. This feature (split group) permits to limit the length of lines in the group file. This is useful to make sure that lines for NIS groups are not larger than 1024 characters. If you need to enforce such limit, you can use 25. Note: split groups may not be supported by all tools (even in the Shadow toolsuite). You should not use this variable unless you really need it. PASS_MAX_DAYS (number) The maximum number of days a password may be used. If the password is older than this, a password change will be forced. If not specified, -1 will be assumed (which disables the restriction). PASS_MIN_DAYS (number) The minimum number of days allowed between password changes. Any password changes attempted sooner than this will be rejected. If not specified, -1 will be assumed (which disables the restriction). PASS_WARN_AGE (number) The number of days warning given before a password expires. A zero means warning is given only upon the day of expiration, a negative value means no warning is given. If not specified, no warning will be provided. SUB_GID_MIN (number), SUB_GID_MAX (number), SUB_GID_COUNT (number) If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate group IDs) allocate SUB_GID_COUNT unused group IDs from the range SUB_GID_MIN to SUB_GID_MAX for each new user. The default values for SUB_GID_MIN, SUB_GID_MAX, SUB_GID_COUNT are respectively 100000, 600100000 and 10000. SUB_UID_MIN (number), SUB_UID_MAX (number), SUB_UID_COUNT (number) If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate user IDs) allocate SUB_UID_COUNT unused user IDs from the range SUB_UID_MIN to SUB_UID_MAX for each new user. The default values for SUB_UID_MIN, SUB_UID_MAX, SUB_UID_COUNT are respectively 100000, 600100000 and 10000. SYS_GID_MAX (number), SYS_GID_MIN (number) Range of group IDs used for the creation of system groups by useradd, groupadd, or newusers. The default value for SYS_GID_MIN (resp. SYS_GID_MAX) is 101 (resp. GID_MIN-1). SYS_UID_MAX (number), SYS_UID_MIN (number) Range of user IDs used for the creation of system users by useradd or newusers. The default value for SYS_UID_MIN (resp. SYS_UID_MAX) is 101 (resp. UID_MIN-1). UID_MAX (number), UID_MIN (number) Range of user IDs used for the creation of regular users by useradd or newusers. The default value for UID_MIN (resp. UID_MAX) is 1000 (resp. 60000). UMASK (number) The file mode creation mask is initialized to this value. If not specified, the mask will be initialized to 022. useradd and newusers use this mask to set the mode of the home directory they create It is also used by pam_umask as the default umask value.
/etc/passwd User account information. /etc/shadow Secure user account information. /etc/group Group account information. /etc/gshadow Secure group account information. /etc/login.defs Shadow password suite configuration. /etc/pam.d/newusers PAM configuration for newusers. /etc/subgid Per user subordinate group IDs. /etc/subuid Per user subordinate user IDs.
login.defs(5), passwd(1), subgid(5), subuid(5), useradd(8).
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.