From mboxrd@z Thu Jan 1 00:00:00 1970 From: mah@mhorton.net (Mary Ann Horton) Date: Thu, 01 Jan 2015 07:59:51 -0800 Subject: [TUHS] I swear! I rtfm'ed In-Reply-To: <54A561A9.6030808@update.uu.se> References: <13336.1420075794@cesium.clock.org> <54A561A9.6030808@update.uu.se> Message-ID: <54A56EF7.60204@mhorton.net> The move was from termcap to terminfo. Termlib was the library for termcap. There were two problems with termcap. One was that the two-character name space was running out of room, and the codes were becoming less and less mnemonic. But the big motivator was performance. Reading in a termcap entry from /etc/termcap was terribly slow. First you had to scan all the way through the (ever-growing) termcap file to find the correct entry. Once you had it, every tgetstr (etc) had to scan from the beginning of the entry, so starting up a program like vi involved quadratic performance (time grew as the square of the length of the termcap entry.) The VAX 11/780 was a 1 MIPS processor (about the same as a 1 MHz Pentium) and was shared among dozens of timesharing users, and some of the other machines of the day (750 and 730 Vaxen, PDP-11, etc.) were even slower. It took forever to start up vi or more or any of the termcap-based programs people were using a lot. I wrote a paper about it for Usenix in 1982, but it seems to be lost to Google. Here is a nice write-up Pavel Curtis posted about it with more detail about the motivation: http://www.informatica.co.cr/unix-source-code/research/1982/0711.html Mary Ann On 01/01/2015 07:03 AM, Johnny Billquist wrote: > On 2015-01-01 02:29, Erik E. Fair wrote: >> All those terminal quirks made writing termcap entries challenging >> (I wrote a few), and made the comments in the termcap file interesting >> reading for the frustration and cursing of terminal firmware authors. >> All kinds of history of the evolution of terminals is captured therein. >> >> The removal of the ability to read the source is - IMHO - what >> greatly impeded adoption of the AT&T "termlib" replacement for >> termcap: they stopped distributing the terminal database source >> (they distributed just the binary "compiled" versions), and made it >> harder to write new entries. > > I was way to removed from the action to know, but why did people > slowly move over to termlib? Was there really any advantages over > termcap? > > Johnny >