id linda
su -
useradd linda
usermod -aG sales linda
sudo
/etc/passwd
vipw
vigr
groupmod
/etc/default/useradd
/etc/login.defs
chage -E 2017-01-30 bob
chage -l bob
/etc/profile
/etc/bashrc
~/.profile
~/.bashrd
/etc/group
LDAP / Kerberos / sssd
authconfig
authconfig-tui
authconfig-gtk
/etc/sssd/sssd.conf
/etc/openldap/ldap.conf
/etc/openldap/cacerts/<fichier.crt>

chown :account folder
chgrp account folder
groups lisa
newgrp sales
chmod
chmod u+s
chmod g+s
chmod +t
getfacl
setfacl
getfacl -R /directory > file.acls
setfacl --restore=file.acls
setfacl -m g:sales:rx /dir
setfacl -m u:linda:rwx /dir
setfacl -m d:g:sales:rx /dir
setfacl -m d:o:- /dir
umask
ACL with user_xattr mount option needed (extX not XFS)
chattr
lsattr