We found a possible problem with teraterm 4.59 telnet and maybe it could be a bug. Can you please give us some comments?
We are testing our telnet server application with various telnet clients (cygwin, linux, teraterm, putty). some default
to linemode, while others including teraterm are character oriented.
for example, cygwin telnet will buffer the operator command "status" locally as it is typed in,
then send it in a single packet when the ENTER key is pressed.
teraterm on the other hand sends single characters one per packet.
while inefficient, it is still OK and the telnet server works with either mode. But what comes at the end of the
operator command determines whether the bug will happen.
a proper line termination is "status\r" (carriage return), or "status\r\n" (
carriage-return new-line)
if teraterm terminal settings are New-line CR (the default), it actually sends \r\0
(0x0d 0x00) and the trailing 0x00 confuses the telnet server command parser
I wonder if this is a bug in teraterm 4.59?
to work around this problem:
A teraterm setting change seems to fix it to make the command properly ended (CR LF). If you go to
Setup -> Terminal... then under New-line Transmit: select CR-LF
that will fix it. To make this the default, just edit c:\Program Files\teraterm\TERATERM.INI
find the line with CRSend=CR and change it to CRSend=CRLF
Subject:[#39003] telnet line ending bug in 4.59
Date:2008-09-24 23:48By:steverino2 (steverino2)We found a possible problem with teraterm 4.59 telnet and maybe it could be a bug. Can you please give us some comments?
We are testing our telnet server application with various telnet clients (cygwin, linux, teraterm, putty). some default
to linemode, while others including teraterm are character oriented.
for example, cygwin telnet will buffer the operator command "status" locally as it is typed in,
then send it in a single packet when the ENTER key is pressed.
teraterm on the other hand sends single characters one per packet.
while inefficient, it is still OK and the telnet server works with either mode. But what comes at the end of the
operator command determines whether the bug will happen.
a proper line termination is "status\r" (carriage return), or "status\r\n" (
carriage-return new-line)
if teraterm terminal settings are New-line CR (the default), it actually sends \r\0
(0x0d 0x00) and the trailing 0x00 confuses the telnet server command parser
I wonder if this is a bug in teraterm 4.59?
to work around this problem:
A teraterm setting change seems to fix it to make the command properly ended (CR LF). If you go to
Setup -> Terminal... then under New-line Transmit: select CR-LF
that will fix it. To make this the default, just edit c:\Program Files\teraterm\TERATERM.INI
find the line with CRSend=CR and change it to CRSend=CRLF
Thank you for your help!