Command Summary
Appendix
Command Name: apropos
Searches the man pages for a command
Command Name: at
Sets up a one-time task for later execution by atd
Useful Options
-l lists all queued tasks (like atq)
-d removes a queued task (like atrm)
Command Name: chmod
Changes the permission assigned to a file or directory
Command Name: chown
Changes the user (owner) and optionally the group assigned to a file or directory
Command Name: df
Displays file system information for all mounted standard file systems (not swap and proc)
Useful Options
-l limits the listing of file systems to local file systems
Command Name: du
Displays usage information about the size of a directory and its subdirectories
Useful Options
-s displays only a summary (total size)
Command Name: file
Displays information about the content and file type of a file
Command Name: find
Searches for files with certain characteristics and lists them or performs other actions on each one
Useful Options
-name filename finds files with the specified filename
-print prints the pathname for each file found
-type file type finds files with the specified access type
-user username finds files owned by the specified user
-perm permission code finds files with the specified file permissions
Command Name: free
Displays the amount of free memory and swap space, with usage details on each
Useful Options
-t includes a line with totals
Command Name: hostname
Displays the hostname of the system
Command Name: ifconfig
Displays or configures the networking interfaces that are part of the Linux kernel
Command Name: locate
Searches an internal index of the file system for any files or directories matching the given string
Command Name: ls
Lists the contents of a directory
Useful Options
-l lists additional (long) format information about each item
-a displays hidden files
--color attempts to list files and directories with color codes by type
-i displays the inode number of each file
Command Name: man
Displays an online manual page for the given command
Command Name: mount
Allows access to a named file system via a named directory mount point
Useful Options
-r makes the file system being mounted read-only
-t specifies the file system type (such as ext2)
Command Name: passwd
Sets or resets the password for a user account
Command Name: ping
Sends a data packet to a network address to test whether that address is reachable
Useful Options
-c count defines how many packets to send
-s packetsize defines how many bytes should be in the packet
Command Name: ps
Displays information about processes running on Linux
Useful Options
-A displays information on all files
u displays user-related fields
x displays information on processes that have no controlling terminal
f displays parent-child relationships of processes in a tree format
Command Name: pwd
Displays the current working directory
Command Name: route
Views or configures the static IP network routing table within the Linux kernel
Command Name: su
Changes to a new user account
Command Name: top
Displays the processes running on the system sorted with the most processor-intensive task listed first
Useful Options
-c displays the command line that initiated each process
-i ignores any idle processes
-s runs top in secure mode, so no interactive keys function
-S runs top in cumulative mode for the CPU time field
Command Name: vmstat
Displays virtual memory (swap space) statistics
Useful Options
-n delay specifies the number of seconds to wait between automatic updates
Command Name: wc
Displays the number of characters, words, and lines in a file or STDIN input stream
Useful Options
-c displays only the number of characters (bytes)
-l displays only the number of lines
-w displays only the number of words
Command Name: who
Displays a list of users who are currently logged in