Revised Telnet byte macro option(1)

　　RFC735DHC RHG 3 Nov 77 42083

　　Telnet Byte Macro Option

　　Network Working Group David H. Crocker

　　RFC: #735 Rand-ISD

　　NIC: #42083 (Dcrocker at Rand-Unix)

　　Richard H. Gumpertz

　　Carnegie-Mellon University

　　(Gumpertz at CMU-10A)

　　Obsoletes: RFC#729 (NIC #40306) 3 November 1977

　　Revised TELNET Byte Macro Option

　　1. Command name and code:

　　BM 19

　　2. Command Meanings:

　　IAC WILL BM

　　The sender of this command REQUESTS or AGREES to use the BM　option, and will send single data characters which are to be　interpreted as if replacement data strings had been sent.

　　IAC WON'T BM

　　The sender of this option REFUSES to send single data characters　which are to be interpreted as if replacement data strings had　been sent. Any existing BM definitions are discarded　(i.e., reset to their original data interpretations).

　　IAC DO BM

　　The sender REQUESTS or AGREES to have the other side (sender of　WILL BM) send single data characters which are to be interpreted　as if replacement data strings had been sent.

　　IAC DON'T BM

　　The sender REFUSES to allow the other side to send single data　characters which are to be interpreted as if replacement data　strings had been sent. Any existing BM definitions　are to be discarded.

　　1

　　RFC735DHC RHG 3 Nov 77 42083

　　Telnet Byte Macro Option

　　IAC SB BM

　　IAC SE

　　where:

　　is the data byte actually to be sent across the　network; it may NOT be Telnet IAC (decimal 255, but may be any　other 8-bit character.

　　is one 8-bit byte binary number, indicating how many　characters follow, up to the ending IAC　SE, but not including it. Note that doubled IACs in the　definition should only be counted as one character per pair.

　　is a string of zero or more Telnet ASCII　characters and/or commands, which the is to　represent; any character may occur within a 　string>. Note, however, that an IAC in the string must be　doubled, to be interpreted later as an IAC; to be interpreted　later as data byte 255, it must be quadrupled in the original　specification.

　　The indicated will be sent instead of the indicated

  　. The receiver of the (the sender　of the DO BM) is to behave EXACTLY as if the 　string of bytes had instead been received from the network. This　interpretation is to occur before any other Telnet　interpretations, unless the occurs as part of a　Telnet command; in this case no special interpretation is to be　made. In particular, an entire Telnet subnegotiation (i.e. from　IAC SB through IAC SE) is to be considered a Telnet command in　which NO replacement should be done.

　　The effect of a particular may be negated by reseting　it to "expand" into itself.

　　IAC SB BM X <0> IAC SE may be used to cause X to be　ignored in the data stream.

　　is decimal 1.

　　IAC SB BM IAC SE

　　The receiver of the for accepts the　requested definition and will perform the indicated replacement　whenever a is received and is not part of any IAC　Telnet command sequence.

　　2

　　RFC735DHC RHG 3 Nov 77 42083

　　Telnet Byte Macro Option　is decimal 2.

　　IAC SB BM IAC SE

　　The receiver of the for refuses to perform　the indicated translation from to 　string> because the particular is not an acceptable　choice, the length of the exceeds available　storage, the length of the actual did not　match the length predicted in the , or for some unspecified　reason.

　　is decimal 3.

　　may be

　　which is decimal 1;

　　(for receiver's storage) which is decimal　2;　(of actual string compared with promised　length in ) which is decimal 3; or　(intended for use only until this document　can be updated to include reasons not　anticipated by the authors) which is　decimal zero (0).

　　IAC SB BM IAC SE

　　The is to be treated as real data, rather than as　representative of the 　Note that this subcommand cannot be used during Telnet　subcommands, since subcommands are defined to end with the next　occurrence of "IAC SE". Including this BM subcommand within any　Telnet subcommand would therefore prematurely terminate the　containing subcommand.