vnc 4.2 KB

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  1. .TH VNC 1
  2. .SH NAME
  3. vncs, vncv \- remote frame buffer server and viewer for Virtual Network Computing (VNC)
  4. .SH SYNOPSIS
  5. .B vncs
  6. [
  7. .B -v
  8. ]
  9. [
  10. .B -c
  11. .I cert
  12. ]
  13. [
  14. .B -d
  15. .BI : display
  16. ]
  17. [
  18. .B -g
  19. .IB width x height
  20. ]
  21. [
  22. .B -p
  23. .I pixfmt
  24. ]
  25. [
  26. .B -x
  27. .I net
  28. ]
  29. [
  30. .I cmd
  31. [
  32. .I args
  33. ...
  34. ]
  35. ]
  36. .PP
  37. .B vncs
  38. .B -k
  39. .BI : display
  40. [
  41. .B -x
  42. .I net
  43. ]
  44. .PP
  45. .B vncv
  46. [
  47. .B -cstv
  48. ]
  49. [
  50. .B -e
  51. .I encodings
  52. ]
  53. [
  54. .B -k
  55. .I keypattern
  56. ]
  57. .IR host [\fL: n ]
  58. .SH DESCRIPTION
  59. VNC is a lightweight protocol
  60. for accessing graphical applications
  61. remotely. The protocol allows one or more
  62. clients to connect to a server.
  63. While connected, clients display the frame buffer
  64. presented by the server and can send mouse events,
  65. keyboard events, and exchange snarf buffers.
  66. The server persists across viewer sessions, so that
  67. the virtual application can be accessed from various locations
  68. as its owner moves around.
  69. .PP
  70. VNC displays have names of the form
  71. .IB host : n \fR,
  72. where
  73. .I host
  74. is the machine's network name and
  75. .I n
  76. is a small integer identifier; display
  77. .I n
  78. is served on TCP port
  79. .RI 5900+ n .
  80. .PP
  81. .I Vncs
  82. starts a new virtual frame buffer in memory, simulating
  83. a Plan 9 terminal running
  84. .I cmd
  85. .IR args ,
  86. by default an interactive shell.
  87. As viewers connect, each is authenticated using a
  88. (rather breakable) challenge-response protocol using
  89. the user's Inferno/POP password.
  90. .PP
  91. The options are:
  92. .TF "\fL-p \fIpixfmt"
  93. .PD
  94. .TP
  95. .B -c \fIcert
  96. start TLS on each viewer connection using the certificate
  97. in the file
  98. .IR cert .
  99. The corresponding private key must be loaded into
  100. the server's
  101. .IR factotum (4).
  102. When serving TLS connections, the base port is
  103. 35729 rather than 5900.
  104. .TP
  105. .B -d :\fIn
  106. run on display
  107. .I n ;
  108. without this option, the server searches
  109. for an unused display.
  110. .TP
  111. .B -g \fIwidth\fBx\fIheight\fR
  112. set the virtual frame buffer to be
  113. .IB width x height
  114. (default
  115. 1024x768)
  116. pixels.
  117. .TP
  118. .B -p \fIpixfmt
  119. set the virtual frame buffer's internal pixel format to
  120. .I pixfmt
  121. (default
  122. .BR r5g6b5 ).
  123. .TP
  124. .B -v
  125. print verbose output to standard error.
  126. .TP
  127. .B -x \fInet
  128. announce on an alternate network interface.
  129. Because of the weak authentication protocol and
  130. default lack of encryption, this option must
  131. be accompanied by
  132. .BR -c .
  133. .PD
  134. .PP
  135. The command
  136. .B vncs
  137. .B -k
  138. .BI : n
  139. kills the VNC server running on display
  140. .IR n .
  141. .PP
  142. .I Vncv
  143. provides access to remote display
  144. .IB host : n \fR.
  145. It resizes its window to be the smaller of the
  146. remote frame buffer size and the local screen.
  147. .PP
  148. The options are:
  149. .TP
  150. .B -c
  151. when connecting to 8-bit displays, request
  152. .B r4g4b4
  153. pixels rather than
  154. .B r3g3b2
  155. pixels.
  156. This takes up more bandwidth but usually gives
  157. significantly better matching to the Plan 9 color map.
  158. .TP
  159. .B -e \fIencodings
  160. set the ordered list of allowed frame buffer update encodings.
  161. The default (and full) set is
  162. .B copyrect
  163. .B corre
  164. .B hextile
  165. .B rre
  166. .BR raw .
  167. The encodings should be given as a single space-separated argument
  168. (quoted when using the shell).
  169. .TP
  170. .B -k \fIkeypattern
  171. add
  172. .I keypattern
  173. to the pattern used to select a key from
  174. .IR factotum (4).
  175. .TP
  176. .B -s
  177. share the display with extant viewers;
  178. by default extant viewers are closed
  179. when a new viewer connects.
  180. .TP
  181. .B -t
  182. start TLS on the connection.
  183. .TP
  184. .B -v
  185. print verbose output to standard error.
  186. .PD
  187. .PP
  188. The VNC protocol represents keyboard input as
  189. key up/down events.
  190. Plan 9 does not expose the state of the
  191. Ctl and Shift keys except as it can be inferred
  192. from receipt of control or shifted characters.
  193. It does not expose the state of the Alt key at all,
  194. since the Alt key is used to compose Unicode characters
  195. (see
  196. .IR keyboard (6)).
  197. .I Vncv
  198. correctly handles the sending of control and shifted
  199. characters.
  200. To support systems that use key sequences like Alt-X
  201. (or worse, Alt-mouse-click), typing the Plan 9 compose
  202. sequences
  203. .B Alt
  204. .B Z
  205. .B A
  206. (for Alt),
  207. .B Alt
  208. .B Z
  209. .B C
  210. (for Ctrl),
  211. and
  212. .B Alt
  213. .B Z
  214. .B S
  215. (for Shift)
  216. will send a ``key down'' message for
  217. the given key.
  218. A corresponding ``key up'' message
  219. will be sent after the next key is pressed,
  220. or when the sequence is retyped,
  221. whichever happens first.
  222. .SH SOURCE
  223. .B /sys/src/cmd/vnc
  224. .SH "SEE ALSO
  225. .IR drawterm (8)
  226. .br
  227. .B http://www.uk.research.att.com/vnc
  228. .SH BUGS
  229. If the remote frame buffer is larger than the local screen,
  230. only the upper left corner can be accessed.
  231. .PP
  232. .I Vncv
  233. does no verification of the TLS certificate presented
  234. by the server.