Question

1. Create customized versions of the /etc/login.defs and /etc/default/useradd files in order to meet the new user account criteria you provide.

2. Research online for various Linux utilities that can be used to store and sort various Linux log files. Have them share their findings with the class.

Answer 1

You can use useradd -r or –system options to create a system account. There is no difference between a system user and a normal user, only 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 /etc/login.defs, instead of UID_MIN-UID_MAX (and their GID counterparts for the creation of groups). Also, for system user useradd will not create a home directory, regardless of the default setting in /etc/login.defs (CREATE_HOME). You have to specify the -m options if you want a home directory for a system account to be created.
You can use useradd -M or –no-create-home options to disable home directory creation even if the system wide setting from /etc/login.defs (CREATE_HOME) is set to yes.
You can use useradd -K or –key KEY=VALUE options to overrides /etc/login.defs defaults (UID_MIN, UID_MAX, UMASK, PASS_MAX_DAYS and others).
You can use useradd -U or –user-group options to create a group with the same name as the user, and add the user to this group. The default behavior (if the -g, -N, and -U options are not specified) is defined by the USERGROUPS_ENAB variable in /etc/login.defs.
You can use useradd -g or –gid GROUP options to add the user to an existing group. -g options accept both group name or number of the user’s initial login group. If not specified, the behavior of useradd will depend on the USERGROUPS_ENAB variable in /etc/login.defs. If this variable is set to yes (or -U/–user-group is specified on the command line), a group will be created for the user, with the same name as her loginname. If the variable is set to no (or -N/–no-user-group is specified on the command line), useradd will set the primary group of the new user to the value specified by the GROUP variable in /etc/default/useradd, or 100 by default.
You can use useradd -N or –no-user-group options to not create a group with the same name as the user, but add the user to the group specified by the -g option or by the GROUP variable in /etc/default/useradd. The default behavior (if the -g, -N, and -U options are not specified) is defined by the USERGROUPS_ENAB variable in /etc/login.defs.