Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!apollo!gallen From: gallen@apollo.uucp (Gary Allen) Newsgroups: comp.unix.questions Subject: Re: Undefined erase/kill characters? Message-ID: <3d1cf0a2.d8e9@apollo.uucp> Date: 7 Jul 88 20:34:00 GMT References: <2652@zyx.SE> Reply-To: gallen@diskless.UUCP (Gary Allen) Organization: Apollo Computer, Chelmsford, MA Lines: 33 In article <2652@zyx.SE> arndt@zyx.SE (Arndt Jonasson) writes: > >The characters to use for erasing a single character and erasing an >entire line, commonly called 'erase' and 'kill' and readble/settable >by the 'stty' command, are stored in a character array pertaining to >the terminal driver, which is updated and read by the 'ioctl' requests >TCGETA/TCSETA/TCSETAF (in SysV) or TIOCGETP/TIOCSETN/TIOCSETP (in >BSD). My question is: can any character (from 0 to 255) be made to, >say, 'erase', or is there some value which indicates "undefined"? The BSD manual defines -1 to be "undefined". >What do Unix systems normally do? Is there a standard for this >(meaning common usage, rather than prescription)? Do the SVID/SVVS >bother to specify this? The only time that I've seen this done is when the port is being used to talk to something other than a terminal, but line buffering is still desired. >A related question: what is supposed to happen when more than one >characters in this array are set to the same value? Which function >is used when the terminal driver sees the character? The BSD manual says that this is "probably unwise". >-- >Arndt Jonasson, ZYX Sweden AB, Styrmansgatan 6, 114 54 Stockholm, Sweden >email address: arndt@zyx.SE or!mcvax!enea!zyx!arndt Gary Allen Apollo Computer Chelmsford, MA {decvax,yale,umix}!apollo!gallen