Linux commands related to user and group (MEMO)

useradd-createanewuserorupdatedefaultnewuserinformation.groupadd-createanewgroupusers-printtheusernamesofuserscurrentlyloggedintothecurrenthost'groups-printthegroupsauserisinid-printrealandeffectiveuserandgroupsIDslistusers-cat/etc/passwd|grep--color^[^:]\\+cat/etc/passwd|awk-F':''{print$1}'listgroups-cat/etc/group|grep--color^[^:]\\+cat/etc/group|awk-F':''{print$1}'[table]