DAY 12 - USERMOD | GROUPADD | GROUPDEL | GPASSWD | ALIAS

r  usermod [options] LOGIN-username
 
v  Modify existing user
v  usermod -g unix <username> [Change Primary Group]
v  usermod -g 1001 <username> [Using GID]
v  usermod -s /bin/bash <username>
v  usermod -g cisco -G linux shohan [G means secondary or supplementary group]
v  usermod -aG cisco shohan [a means appends]

r  groupadd [options] group
 
v  Add group in the system
v  groupadd linux
v  Groupadd -g 1010 linux

r  groupdel [options] group
 
v  Delete group from system
v  groupdel linux

r  gpasswd [option] group
 
v  Add secondary group
v  gpasswd -a <username> <GroupName> [a means adds]
v  gpasswd -d <username> <GroupName> [d means delete]
v  gpasswd -M <username1>, <username2>, <username3> <GroupName> [M means members]

r  getent [database] [key]
 
v  It will search user from passwd/group database
v  getent passwd <username>
v  getent group <username>

r  chsh -l [Check how many shells are available in the system]

v  /bin/sh
v  /bin/bash
v  /usr/bin/sh
v  /usr/bin/bash
v  /bin/tcsh
v  /bin/csh
v  /bin/ksh
v  /bin/rksh
v  /usr/bin/tmux

r  echo $SHELL

r  Alias – means shortcut

·        vi /etc/bashrc [as root user]
·        alias c=clear [write command under above file]

r  vi .bash_logout