mirror of
https://github.com/lwip-tcpip/lwip.git
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53 lines
2.2 KiB
Plaintext
53 lines
2.2 KiB
Plaintext
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CHARGEN
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This file implements a nice example of handling multiple tcp sockets in a
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server environment. Just call chargen_init() from your application after
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you have initialized lwip and added your network interfaces. Change the
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MAX_SERV option to increase or decrease the number of sessions supported.
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chargen will jam as much data as possible into the output socket, so it
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will take up a lot of CPU time. Therefore it will be a good idea to run it
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as the lowest possible priority (just ahead of any idle task).
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This is also a good example of how to support multiple sessions in an
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embedded system where you might not have fork(). The multiple sessions are
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all handled by the same thread and select() is used for demultiplexing.
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No makefile is provided, just add chargen to the makefile for your
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application. It is OS and HW independent.
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Once the chargen server is running in your application, go to another system
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and open a telnet session to your lwip platform at port 19. You should see an
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ASCII pattern start to stream on you screen.
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As an example, lets say that your system running lwip is at IP address
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192.168.10.244 and you have a linux system connected to it at IP address
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192.168.10.59. Issue the following command at a terminal prompt on the linux system:
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telnet 192.168.10.244 19
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You will see a pattern similar to the following on streaming by on your
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screen:
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ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{
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BCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|
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CDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}
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DEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
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EFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!
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FGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"
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GHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#
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HIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#$
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IJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#$%
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JKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#$%&
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KLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#$%&'
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LMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#$%&'(
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It even works from windows: At a dos prompt you can also issue the same
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telnet command and you will get a similar (but much slower, at least on W98)
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data stream.
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David Haas
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