echo date ps wget kill killall pidof poweroff top reboot
ifconfig free uname uptime history who last
pwd ls cd cat more tailf haed diff stat tr wc cut
touch dd cp mv rm mkdir file tar find grep
alias unalias bashrc basename bc clock cal 9 1752
command alias cat vi /etc/centos-release /proc/meminfo /etc/profile
dd df dirname du -sh /* echo enable fdisk free
hash hostname id init lsblk ltrace ldd ntpdate
passwd type startx source screen sudo hostname centos7
uname wall w who who am i whoami
whatis whereis which vi /etc/sysconfig/network