Man page 8 : iwlist

iwlist - Get more detailed wireless information from a wireless interface

iwlist [ interface ] scanning
iwlist [ interface ] frequency
iwlist [ interface ] rate
iwlist [ interface ] keys
iwlist [ interface ] power
iwlist [ interface ] txpower
iwlist [ interface ] retry
iwlist [ interface ] event
iwlist [ interface ] auth
iwlist [ interface ] wpakeys
iwlist [ interface ] genie
iwlist [ interface ] modulation
iwlist --help
iwlist --version

Iwlist is used to display some additional information from a wireless network interface that is not displayed by iwconfig (8). The main argument is used to select a category of information,

iwlist displays in detailed form all information related to this category, including information already shown by iwconfig (8).

R scan [ning]

    Give the list of Access Points and Ad-Hoc cells in range, and optionally a whole bunch of information about them (ESSID, Quality, Frequency, Mode...). The type of information returned depends on what the card supports.
Triggering scanning is a privileged operation ( root only) and normal users can only read left-over scan results. By default, the way scanning is done (the scope of the scan) is dependant on the card and card settings.
This command takes optional arguments, however most drivers will ignore those. The option

essid is used to specify a scan on a specific ESSID. With some card/driver, this enables to see hidden networks. The option

last does not trigger a scan and read left-over scan results.

R freq [uency]/ channel

    Give the list of available frequencies in the device and the number of defined channels. Please note that usually the driver returns the total number of channels and only the frequencies available in the present locale, so there is no one-to-one mapping between frequencies displayed and channel numbers.

R rate / bit [rate]

    List the bit-rates supported by the device.

R keys / enc [ryption]

    List the encryption key sizes supported and list all the encryption keys set in the device.

power

    List the various Power Management attributes and modes of the device.

txpower

    List the various Transmit Powers available on the device.

retry

    List the transmit retry limits and retry lifetime on the device.

R ap / accesspoint / peers

    Give the list of Access Points in range, and optionally the quality of link to them. This feature is

obsolete and now deprecated in favor of scanning support (above), and most drivers don't support it.
Some drivers may use this command to return a specific list of Peers or Access Points, such as the list of Peers associated/registered with the card. See your driver documentation for details.

event

    List the wireless events supported by the device.

auth

    List the WPA authentication parametes curently set.

R wpa [keys]

    List all the WPA encryption keys set in the device.

genie

    List the Generic Information Elements set in the device (used for WPA support).

R modu [lation]

    List the modulations supported by the device and the modulations currently enabled.

--version

    Display the version of the tools, as well as the recommended and current Wireless Extensions version for the tool and the various wireless interfaces.

--help

    Display short help message.

/proc/net/wireless

R iwconfig (8),

R iwspy (8).

R iwevent (8),

R iwpriv (8),

R wireless (7).