tgl@zog.cs.cmu.edu (Tom Lane) (03/28/90)
I've been trying to use the curses(3) library package for a program that wants to pop-up an inverse-video window for error messages and such. I've found that this works well enough on some terminals, but the performance *really sucks* when dealing with an HP 360 console or with the "hpterm" X terminal emulator. In both of these cases curses outputs incredibly inefficient sequences to make the window area become or cease to be inverse video. (These are "300h" and "hp2622" terminfo types.) This seems to be related to use of the "xmc" and "xhp" terminfo capabilities, but I haven't figured out exactly what the semantics of these are. In particular, the manual makes it appear that the "xmc#0" appearing in the database should be a no-op, but experimentation proves that it ain't. I'm running HPUX 6.2. Does anybody know if this problem has been repaired in more recent system versions? Alternately, has anyone prepared a better terminfo description for these terminal types? -- tom lane Internet: tgl@cs.cmu.edu UUCP: <your favorite internet/arpanet gateway>!cs.cmu.edu!tgl BITNET: tgl%cs.cmu.edu@cmuccvma CompuServe: >internet:tgl@cs.cmu.edu
roskuski@mirror.tmc.com (Barry Roskuski) (03/28/90)
In article <8618@pt.cs.cmu.edu> tgl@zog.cs.cmu.edu (Tom Lane) writes: >I've been trying to use the curses(3) library package for a program >that wants to pop-up an inverse-video window for error messages and >such. I've found that this works well enough on some terminals, but >the performance *really sucks* when dealing with an HP 360 console or >with the "hpterm" X terminal emulator. In both of these cases curses >outputs incredibly inefficient sequences to make the window area >become or cease to be inverse video. (These are "300h" and "hp2622" >terminfo types.) On the 300h and hp2622 terminals (and many other HP terminals), the character attributes work differently than on terminals like the VT100, which curses deals with much better. Turning on an inverse video, for example will turn on the inverse video for any character on that line to the right of the character position you are now on, until you come to either LF or a inverse video off attribute. On a VT100 turning on the inverse video attribute means all chracters actually written after turning the attribute on will be inverse video, until you turn the attribute off. xhp is a flag to curses saying you have HP style attributes. Those incredibly inneficient escape sequences are there to guarantee that the terminal will behave like a VT100 (which curses knows how to deal with.). What I am saying here is that if you want to use attributes and curses on HP terminals, you are stuck with this behavior. Sorry the news couldn't be better. --- Barry J. Roskuski Mirror Systems 2067 Massachusetts Ave. Cambridge, MA 01240 roskuski@mirror.TMC.COM {mit-eddie, pyramid, harvard!wjh12, xait}!mirror!roskuski