+-----------------------------------------------------------------------------+
|                                                                             |
|         Linux - CLI - Command line system information query commands        |
|                                                                             |
+-----------------------------------------------------------------------------+
| lsn; 20020409; created documentation		                              |
| lsn; 20020725; added commands			                              |
| lsn; 20030919; revised structure and added more commands                    |
+-----------------------------------------------------------------------------+

      Note: Some of the following commands may or may not work on your
            particular distribution depending on whether or not the
            package containing the command has been installed.  Also,
            some of the commands/files may only be accessed as root.

+--------------------------------- VERSION -----------------------------------+

command: uname		(print system version information)

 - usage: uname -a


file: /etc/issue	(contains Linux release number and Kernel version)

 - usage: cat /etc/issue


file: /etc/issue.net	(contains Linux release number and Kernel version)

 - usage: cat /etc/issue.net

	--> The difference between issue & issue.net is: issue contains
            the information that is reported to the local shell, whereas
            issue.net contains information that is reported to a remote
            shell.
 
+--------------------------------- MEMORY ------------------------------------+ 

command: free		(display amount of free and used memory in the system)

 - usage: free -m


file: /proc/meminfo	(a slightly different listing of memory utilization)

 - usage: cat /proc/meminfo

+--------------------------------- CPU ---------------------------------------+ 

command: top		(display top CPU processes)

 - usage: top 

+--------------------------------- PROCESSES ---------------------------------+ 

command: ps		(report process status)

 - usage: ps -ef |more


command: pstree		(display a tree of processes)

 - usage: pstree -hacup |more

+--------------------------------- SYSTEM MESSAGES ---------------------------+ 

command: dmesg		(print or control the kernel ring buffer)

 - usage: dmesg |more


file: /var/log/messages	(where system messages & error messages are stored)

 - usage: more /var/log/messages

+--------------------------------- HARDWARE DEVICES --------------------------+ 

command: lsdev		(display information about installed hardware)

 - options: none

+--------------------------------- CPU ---------------------------------------+ 

file: /proc/cpuinfo	(contains info about your processor)

 - usage: cat /proc/cpuinfo

+--------------------------------- PCI ---------------------------------------+ 

command: lspci		(list all PCI devices)

 - usage: lspci or lspci -v


file: /proc/pci		(contains information about pci devices in your system)

 - usage: cat /proc/pci |more

+--------------------------------- PROC --------------------------------------+ 

command: procinfo	(display system status gathered from /proc)

 - usage: procinfo -a |more

+--------------------------------- SOCKETS -----------------------------------+ 

command: socklist	(display list of open sockets)

 - options: none

+--------------------------------- NETWORK STATUS ----------------------------+ 

command: netstat  (Print network connections, routing tables, interface stats,
                  masquerade connections, and multicast memberships)

 - options: many

 - usage: netstat -an |more

+--------------------------------- FILES -------------------------------------+ 

command: lsof		(list open files)

 - options: many

 - usage: /usr/sbin/lsof -i tcp:<portnumber>

+--------------------------------- LIBRARY FILES -----------------------------+ 

command: ldd		(print shared library dependencies)

 - usage: locate lsof
          file /usr/sbin/lsof
          ldd -d /usr/sbin/lsof

+--------------------------------- FILE TYPES --------------------------------+ 

command: file		(determine file type)

 - usage:   file <filename>	example: file ldd
 - output:  /usr/bin/ldd: Bourne shell script text

+--------------------------------- WHICH FILES -------------------------------+ 

command: which		(shows the full path of shell commands)

 - usage:   which <filename>	example: which ldd
 - output:  /usr/bin/ldd

+--------------------------------- WHEREIS -----------------------------------+ 

command: whereis	(locate the binary, source, & man page files)

 - usage: whereis <filename>	example: whereis ldd
 - output:  ldd: /usr/bin/ldd /usr/man/man1/ldd.1

+--------------------------------- WHO ---------------------------------------+ 

command: who		(show who is logged on)

 - usage: who

+--------------------------------- DF ----------------------------------------+ 

command: df		(report filesystem disk space usage)

 - options: many

 - usage: df -h

+--------------------------------- UPTIME ------------------------------------+ 

command: uptime		(tell how long the system has been running)

+--------------------------------- LOCATE ------------------------------------+ 

command: locate		(find files on your system)

 - usage: locate <filename> |more

+--------------------------------- X -----------------------------------------+ 

command: X -version	(tell me what version of X I am running)

+--------------------------------------end------------------------------------+