R02RDK@DHHDESY3.BITNET (Raymond Koluvek) (02/21/89)
Could someone tell me if it is allowed from an user application under
a Telnet client, to have access to the Telnet command
structure, e.g. could the Telnet client application progarm
send a 0xff 0xf8 through Telnet have it interperted as erase line,
or will the Telnet client escape it as 0xff 0xff 0xf8.
Thanks, Ray
Raymond D. Koluvek
(Deutsches Eletronen - Synchrotron, DESY)
Buggy
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Email : R02RDK@DHHDESY3.BITNEThedrick@geneva.rutgers.edu (Charles Hedrick) (02/21/89)
If you send 0xff through a telnet connection, it gets escaped to 0xff 0xff, so that the other end knows not to take it as a command. This means that programs running in a telnet session can't issue telnet commands. There's a group working on something called "line mode telnet", which is in fact a way to allow the server machine to pass terminal mode changes to the user machine. So rather than sending explicit telnet commands, you'll just issue the appropriate system calls to your OS to do whatever you want done, just as you would for a directly connected terminal. However your specific example was sending an erase line. I'm not sure quite what effect you expect if a program sent an erase line command. Normally erase line would be sent from the user telnet to the server telnet, and it would translate into ^U, #, or whatever causes your OS to erase a line. I'm not sure what it would mean to send it outwards from a program. Certainly user telnets are not going to erase a line from the screen when they see this command from the host.
jbvb@ftp.COM (James Van Bokkelen) (02/22/89)
In article <8902200941.aa14870@louie.udel.edu>, R02RDK@DHHDESY3.BITNET (Raymond Koluvek) writes: > ......, e.g. could the Telnet client application progarm > send a 0xff 0xf8 through Telnet have it interperted as erase line, > or will the Telnet client escape it as 0xff 0xff 0xf8. > Unless there is some special call the application can make to turn it off when necessary, the Telnet client *must* always insert the 2nd 0xFF. -- James B. VanBokkelen We're moving. After 2/26, the new number FTP Software Inc. will be (617) 246-0900.