Commands to display system information

ulimit
------------------
Provides control over the resources available
to the shell and to processes started by it
(setting size of core file)

ipcs
------------------
report XSI interprocess communication facilities status

free
------------------
[sandesh@sandeshks ~]$ free
total used free shared buffers cached
Mem: 1026828 547940 478888 0 36128 212776
-/+ buffers/cache: 299036 727792
Swap: 2031608 189572 1842036


top
------------------

vmstat
------------------
Report virtual memory statistics


lspci
lspci -vv : very verbose
------------------
Utility for displaying information about all PCI buses in the system and all devices connected to them.


lsdev - display information about installed hardware
------------------
lsdev gathers information about your computer's installed hardware from the
interrupts, ioports and dma files in the /proc directory, thus giving you a quick
overview of which hardware uses what I/O addresses and what IRQ and
DMA channels.


lsusb - list USB devices
------------------
lsusb is a utility for displaying information about USB buses in the system and the
devices connected to them.

For information on GNU core utilities type
info coreutils