Command Description*cat [filename] Display file’s contents to the standard output device (usually your monitor). *cd /directorypath Change to directory. *chmod [options] mode filename Change a file’s permissions. *chown [options] filename Change who owns a file. *clear Clear a command line screen/window for a fresh start. *cp [options] source destination Copy files and directories. *date [options] Display or set the system date and time. *df [options] Display used and available disk space. *du [options] Show how much space each file takes up. *file [options] filename Determine what type of data is within a file. *find [pathname] [expression] Search for files matching a provided pattern. *grep [options] pattern [filesname] Search files or output for a particular pattern. *kill [options] pid Stop a process. If the process refuses to stop, use kill -9 pid. *less [options] [filename] View the contents of a file one page at a time. *ln [options] source [destination] Create a shortcut. *locate filename Search a copy of your filesystem for the specified filename. *lpr [options] Send a print job. *ls [options] List directory contents. */man [command] Display the help information for the specified command. *mkdir [options] directory Create a new directory. *mv [options] source destination Rename or move file(s) or directories. *passwd [name [password]] Change the password or allow (for the system administrator) to change any password. *ps [options] Display a snapshot of the currently running processes. *pwd Display the pathname for the current directory. *rm [options] directory Remove (delete) file(s) and/or directories. *rmdir [options] directory Delete empty directories. *ssh [options] user@machine Remotely log in to another Linux machine, over the network. *Leave an ssh session by typing exit. *su [options] [user [arguments]] Switch to another user account. *tail [options] [filename] Display the last n lines of a file (the default is 10). *tar [options] filename Store and extract files from a tarfile (.tar) or tarball (.tar.gz or .tgz). *top Displays the resources being used on your system. Press q to exit. *touch filename Create an empty file with the specified name. *who [options] Display who is logged on.