$ ldconfig -p    # list shared libraries cache

# ldconfig    # refresh shared libraries cache

$ ls | cpio -ov > archive.cpio    # create an archive with cpio

$ pstree -pha    # display hierarchical list of processes

$ renice 20 100    # lower the priority of the process with pid=100

# netstat -anp --tcp    # display TCP connections

# lsof -i    # display network connections

# lsof -u <user>    # display files opened by given user

# ldd <executable>    # display shared library dependencies

# runlevel    # show current and previous runlevels

# chkconfig --list    # list services along with their runlevels

# initcrl --list    # view currently running jobs (Upstart)

# mkswap <device>     # create swap partition

# swapon -s    # list swap spaces that are on

# getfacl <file>    # grap ACL information

# setfacl -m u:<user>:<permissions> <file>    # set ACL permissions

# setfacl -x u:<user> <file>    # clear ACL permissions for the user

# setfacl -b <file>    # clear all custom ACL permissions

# route add defalut gw <ip> <iface>    # define default route

$ tree -pugsh    # display indented directory tree

$ head -c16 /dev/urandom | base64    # generate random key

$ ps -FA    # display all processes

$ ps -F -u <user>    # display processes of given user

$ ps -FC <process>    # display the process (if any)

# sysv-rc-conf    # visual manager for SysV RC