2 A Hacker's Guide to NCURSES
7 * Objective of the Package
9 + How to Design Extensions
10 * Portability and Configuration
12 * Documentation Conventions
14 * A Tour of the Ncurses Library
19 + Output and Screen Updating
20 * The Forms and Menu Libraries
21 * A Tour of the Terminfo Compiler
22 + Translation of Non-use Capabilities
23 + Use Capability Resolution
24 + Source-Form Translation
26 * Style Tips for Developers
31 This document is a hacker's tour of the ncurses library and utilities.
32 It discusses design philosophy, implementation methods, and the
33 conventions used for coding and documentation. It is recommended
34 reading for anyone who is interested in porting, extending or
35 improving the package.
37 Objective of the Package
39 The objective of the ncurses package is to provide a freeware API for
40 character-cell terminals and terminal emulators with the following
43 * Source-compatible with historical curses implementations
44 (including the original BSD curses and System V curses.
45 * Conformant with the XSI Curses standard issued as part of XPG4 by
47 * High-quality -- stable and reliable code, wide portability, good
48 packaging, superior documentation.
49 * Featureful -- should eliminate as much of the drudgery of C
50 interface programming as possible, freeing programmers to think at
51 a higher level of design.
53 These objectives are in priority order. So, for example, source
54 compatibility with older version must trump featurefulness -- we
55 cannot add features if it means breaking the portion of the API
56 corresponding to historical curses versions.
60 We used System V curses as a model, reverse-engineering their API, in
61 order to fulfill the first two objectives.
63 System V curses implementations can support BSD curses programs with
64 just a recompilation, so by capturing the System V API we also capture
67 More importantly for the future, the XSI Curses standard issued by
68 X/Open is explicitly and closely modeled on System V. So conformance
69 with System V took us most of the way to base-level XSI conformance.
71 How to Design Extensions
73 The third objective (standards conformance) requires that it be easy
74 to condition source code using ncurses so that the absence of
75 nonstandard extensions does not break the code.
77 Accordingly, we have a policy of associating with each nonstandard
78 extension a feature macro, so that ncurses client code can use this
79 macro to condition in or out the code that requires the ncurses
82 For example, there is a macro NCURSES_MOUSE_VERSION which XSI Curses
83 does not define, but which is defined in the ncurses library header.
84 You can use this to condition the calls to the mouse API calls.
86 Portability and Configuration
88 Code written for ncurses may assume an ANSI-standard C compiler and
89 POSIX-compatible OS interface. It may also assume the presence of a
90 System-V-compatible select(2) call.
92 We encourage (but do not require) developers to make the code friendly
93 to less-capable UNIX environments wherever possible.
95 We encourage developers to support OS-specific optimizations and
96 methods not available under POSIX/ANSI, provided only that:
98 * All such code is properly conditioned so the build process does
99 not attempt to compile it under a plain ANSI/POSIX environment.
100 * Adding such implementation methods does not introduce
101 incompatibilities in the ncurses API between platforms.
103 We use GNU autoconf(1) as a tool to deal with portability issues. The
104 right way to leverage an OS-specific feature is to modify the autoconf
105 specification files (configure.in and aclocal.m4) to set up a new
106 feature macro, which you then use to condition your code.
110 The 'configure' script usually gets your system environment right
111 automatically. Here are some -D options you might need to compile with
115 if <unistd.h> is present
118 if the sigaction function is present
121 if the usleep function is present
124 if (e.g., svr4) you need _POSIX_SOURCE to have sigaction
127 if you have <termios.h>
130 if you have <termio.h>; otherwise it uses <sgtty.h>
132 -DBROKEN_TIOCGETWINSZ
133 on SVR4 and HPUX, the get window size ioctl is broken.
135 Documentation Conventions
137 There are three kinds of documentation associated with this package.
138 Each has a different preferred format:
140 * Package-internal files (README, INSTALL, TO-DO etc.)
142 * Everything else (i.e., narrative documentation).
144 Our conventions are simple:
146 1. Maintain package-internal files in plain text. The expected viewer
147 for them more(1) or an editor window; there's no point in
149 2. Mark up manual pages in the man macros. These have to be viewable
150 through traditional man(1) programs.
151 3. Write everything else in HTML.
153 When in doubt, HTMLize a master and use lynx(1) to generate plain
154 ASCII (as we do for the announcement document).
156 The reason for choosing HTML is that it's (a) well-adapted for on-line
157 browsing through viewers that are everywhere; (b) more easily readable
158 as plain text than most other mark-ups, if you don't have a viewer;
159 and (c) carries enough information that you can generate a
160 nice-looking printed version from it. Also, of course, it make
161 exporting things like the announcement document to WWW pretty trivial.
165 The reporting address for bugs is bug-ncurses@gnu.org. This is a
166 majordomo list; to join, write to ncurses-request@gnu.org with a
167 message containing the line:
168 subscribe <name>@<host.domain>
170 The ncurses code is maintained by a small group of volunteers. While
171 we try our best to fix bugs promptly, we simply don't have a lot of
172 hours to spend on elementary hand-holding. We rely on intelligent
173 cooperation from our users. If you think you have found a bug in
174 ncurses, there are some steps you can take before contacting us that
175 will help get the bug fixed quickly.
177 In order to use our bug-fixing time efficiently, we put people who
178 show us they've taken these steps at the head of our queue. This means
179 that if you don't, you'll probably end up at the tail end and have to
182 1. Develop a recipe to reproduce the bug.
183 Bugs we can reproduce are likely to be fixed very quickly, often
184 within days. The most effective single thing you can do to get a
185 quick fix is develop a way we can duplicate the bad behavior --
186 ideally, by giving us source for a small, portable test program
187 that breaks the library. (Even better is a keystroke recipe using
188 one of the test programs provided with the distribution.)
189 2. Try to reproduce the bug on a different terminal type.
190 In our experience, most of the behaviors people report as library
191 bugs are actually due to subtle problems in terminal descriptions.
192 This is especially likely to be true if you're using a traditional
193 asynchronous terminal or PC-based terminal emulator, rather than
194 xterm or a UNIX console entry.
195 It's therefore extremely helpful if you can tell us whether or not
196 your problem reproduces on other terminal types. Usually you'll
197 have both a console type and xterm available; please tell us
198 whether or not your bug reproduces on both.
199 If you have xterm available, it is also good to collect xterm
200 reports for different window sizes. This is especially true if you
201 normally use an unusual xterm window size -- a surprising number
202 of the bugs we've seen are either triggered or masked by these.
203 3. Generate and examine a trace file for the broken behavior.
204 Recompile your program with the debugging versions of the
205 libraries. Insert a trace() call with the argument set to
206 TRACE_UPDATE. (See "Writing Programs with NCURSES" for details on
207 trace levels.) Reproduce your bug, then look at the trace file to
208 see what the library was actually doing.
209 Another frequent cause of apparent bugs is application coding
210 errors that cause the wrong things to be put on the virtual
211 screen. Looking at the virtual-screen dumps in the trace file will
212 tell you immediately if this is happening, and save you from the
213 possible embarrassment of being told that the bug is in your code
214 and is your problem rather than ours.
215 If the virtual-screen dumps look correct but the bug persists,
216 it's possible to crank up the trace level to give more and more
217 information about the library's update actions and the control
218 sequences it issues to perform them. The test directory of the
219 distribution contains a tool for digesting these logs to make them
220 less tedious to wade through.
221 Often you'll find terminfo problems at this stage by noticing that
222 the escape sequences put out for various capabilities are wrong.
223 If not, you're likely to learn enough to be able to characterize
224 any bug in the screen-update logic quite exactly.
225 4. Report details and symptoms, not just interpretations.
226 If you do the preceding two steps, it is very likely that you'll
227 discover the nature of the problem yourself and be able to send us
228 a fix. This will create happy feelings all around and earn you
229 good karma for the first time you run into a bug you really can't
230 characterize and fix yourself.
231 If you're still stuck, at least you'll know what to tell us.
232 Remember, we need details. If you guess about what is safe to
233 leave out, you are too likely to be wrong.
234 If your bug produces a bad update, include a trace file. Try to
235 make the trace at the least voluminous level that pins down the
236 bug. Logs that have been through tracemunch are OK, it doesn't
237 throw away any information (actually they're better than
238 un-munched ones because they're easier to read).
239 If your bug produces a core-dump, please include a symbolic stack
240 trace generated by gdb(1) or your local equivalent.
241 Tell us about every terminal on which you've reproduced the bug --
242 and every terminal on which you can't. Ideally, sent us terminfo
243 sources for all of these (yours might differ from ours).
244 Include your ncurses version and your OS/machine type, of course!
245 You can find your ncurses version in the curses.h file.
247 If your problem smells like a logic error or in cursor movement or
248 scrolling or a bad capability, there are a couple of tiny test frames
249 for the library algorithms in the progs directory that may help you
250 isolate it. These are not part of the normal build, but do have their
251 own make productions.
253 The most important of these is mvcur, a test frame for the
254 cursor-movement optimization code. With this program, you can see
255 directly what control sequences will be emitted for any given cursor
256 movement or scroll/insert/delete operations. If you think you've got a
257 bad capability identified, you can disable it and test again. The
258 program is command-driven and has on-line help.
260 If you think the vertical-scroll optimization is broken, or just want
261 to understand how it works better, build hashmap and read the header
262 comments of hardscroll.c and hashmap.c; then try it out. You can also
263 test the hardware-scrolling optimization separately with hardscroll.
265 There's one other interactive tester, tctest, that exercises
266 translation between termcap and terminfo formats. If you have a
267 serious need to run this, you probably belong on our development team!
269 A Tour of the Ncurses Library
273 Most of the library is superstructure -- fairly trivial convenience
274 interfaces to a small set of basic functions and data structures used
275 to manipulate the virtual screen (in particular, none of this code
276 does any I/O except through calls to more fundamental modules
277 described below). The files lib_addch.c, lib_bkgnd.c, lib_box.c,
278 lib_clear.c, lib_clrbot.c, lib_clreol.c, lib_data.c, lib_delch.c,
279 lib_delwin.c, lib_erase.c, lib_getstr.c, lib_inchstr.c, lib_insch.c,
280 lib_insdel.c, lib_insstr.c, lib_instr.c, lib_isendwin.c,
281 lib_keyname.c, lib_move.c, lib_mvwin.c, lib_overlay.c, lib_pad.c,
282 lib_printw.c, lib_scanw.c, lib_screen.c, lib_scroll.c, lib_scrreg.c,
283 lib_set_term.c, lib_slk.c, lib_touch.c, lib_unctrl.c, and lib_window.c
284 are all in this category. They are very unlikely to need change,
285 barring bugs or some fundamental reorganization in the underlying data
288 The lib_trace.c, lib_traceatr.c, and lib_tracechr.c file are used only
289 for debugging support. It is rather unlikely you will ever need to
290 change these, unless you want to introduce a new debug trace level for
293 There is another group of files that do direct I/O via tputs(),
294 computations on the terminal capabilities, or queries to the OS
295 environment, but nevertheless have only fairly low complexity. These
296 include: lib_acs.c, lib_beep.c, lib_color.c, lib_endwin.c,
297 lib_initscr.c, lib_longname.c, lib_newterm.c, lib_options.c,
298 lib_termcap.c, lib_ti.c, lib_tparm.c, lib_tputs.c, lib_vidattr.c, and
299 read_entry.c. These are likely to need revision only if ncurses is
300 being ported to an environment without an underlying terminfo
301 capability representation.
303 The files lib_kernel.c, lib_baudrate.c, lib_raw.c, lib_tstp.c, and
304 lib_twait.c have serious hooks into the tty driver and signal
305 facilities. If you run into porting snafus moving the package to
306 another UNIX, the problem is likely to be in one of these files. The
307 file lib_print.c uses sleep(2) and also falls in this category.
309 Almost all of the real work is done in the files hashmap.c,
310 hardscroll.c, lib_addch.c, lib_doupdate.c, lib_mvcur.c, lib_getch.c,
311 lib_mouse.c, lib_refresh.c, and lib_setup.c. Most of the algorithmic
312 complexity in the library lives in these files. If there is a real bug
313 in ncurses itself, it's probably here. We'll tour some of these files
314 in detail below (see The Engine Room).
316 Finally, there is a group of files that is actually most of the
317 terminfo compiler. The reason this code lives in the ncurses library
318 is to support fallback to /etc/termcap. These files include
319 alloc_entry.c, captoinfo.c, comp_captab.c, comp_error.c, comp_hash.c,
320 comp_parse.c, comp_scan.c, and parse_entry.c, read_termcap.c, and
321 write_entry.c. We'll discuss these in the compiler tour.
327 All ncurses input funnels through the function wgetch(), defined in
328 lib_getch.c. This function is tricky; it has to poll for keyboard and
329 mouse events and do a running match of incoming input against the set
330 of defined special keys.
332 The central data structure in this module is a FIFO queue, used to
333 match multiple-character input sequences against special-key
334 capabilities; also to implement pushback via ungetch().
336 The wgetch() code distinguishes between function key sequences and the
337 same sequences typed manually by doing a timed wait after each input
338 character that could lead a function key sequence. If the entire
339 sequence takes less than 1 second, it is assumed to have been
340 generated by a function key press.
342 Hackers bruised by previous encounters with variant select(2) calls
343 may find the code in lib_twait.c interesting. It deals with the
344 problem that some BSD selects don't return a reliable time-left value.
345 The function timed_wait() effectively simulates a System V select.
349 If the mouse interface is active, wgetch() polls for mouse events each
350 call, before it goes to the keyboard for input. It is up to
351 lib_mouse.c how the polling is accomplished; it may vary for different
354 Under xterm, however, mouse event notifications come in via the
355 keyboard input stream. They are recognized by having the kmous
356 capability as a prefix. This is kind of klugey, but trying to wire in
357 recognition of a mouse key prefix without going through the
358 function-key machinery would be just too painful, and this turns out
359 to imply having the prefix somewhere in the function-key capabilities
360 at terminal-type initialization.
362 This kluge only works because kmous isn't actually used by any
363 historic terminal type or curses implementation we know of. Best guess
364 is it's a relic of some forgotten experiment in-house at Bell Labs
365 that didn't leave any traces in the publicly-distributed System V
366 terminfo files. If System V or XPG4 ever gets serious about using it
367 again, this kluge may have to change.
369 Here are some more details about mouse event handling:
371 The lib_mouse()code is logically split into a lower level that accepts
372 event reports in a device-dependent format and an upper level that
373 parses mouse gestures and filters events. The mediating data structure
374 is a circular queue of event structures.
376 Functionally, the lower level's job is to pick up primitive events and
377 put them on the circular queue. This can happen in one of two ways:
378 either (a) _nc_mouse_event() detects a series of incoming mouse
379 reports and queues them, or (b) code in lib_getch.c detects the kmous
380 prefix in the keyboard input stream and calls _nc_mouse_inline to
381 queue up a series of adjacent mouse reports.
383 In either case, _nc_mouse_parse() should be called after the series is
384 accepted to parse the digested mouse reports (low-level events) into a
385 gesture (a high-level or composite event).
387 Output and Screen Updating
389 With the single exception of character echoes during a wgetnstr() call
390 (which simulates cooked-mode line editing in an ncurses window), the
391 library normally does all its output at refresh time.
393 The main job is to go from the current state of the screen (as
394 represented in the curscr window structure) to the desired new state
395 (as represented in the newscr window structure), while doing as little
398 The brains of this operation are the modules hashmap.c, hardscroll.c
399 and lib_doupdate.c; the latter two use lib_mvcur.c. Essentially, what
400 happens looks like this:
402 The hashmap.c module tries to detect vertical motion changes between
403 the real and virtual screens. This information is represented by the
404 oldindex members in the newscr structure. These are modified by
405 vertical-motion and clear operations, and both are re-initialized
406 after each update. To this change-journalling information, the hashmap
407 code adds deductions made using a modified Heckel algorithm on hash
408 values generated from the line contents.
410 The hardscroll.c module computes an optimum set of scroll, insertion,
411 and deletion operations to make the indices match. It calls
412 _nc_mvcur_scrolln() in lib_mvcur.c to do those motions.
414 Then lib_doupdate.c goes to work. Its job is to do line-by-line
415 transformations of curscr lines to newscr lines. Its main tool is the
416 routine mvcur() in lib_mvcur.c. This routine does cursor-movement
417 optimization, attempting to get from given screen location A to given
418 location B in the fewest output characters posible.
420 If you want to work on screen optimizations, you should use the fact
421 that (in the trace-enabled version of the library) enabling the
422 TRACE_TIMES trace level causes a report to be emitted after each
423 screen update giving the elapsed time and a count of characters
424 emitted during the update. You can use this to tell when an update
425 optimization improves efficiency.
427 In the trace-enabled version of the library, it is also possible to
428 disable and re-enable various optimizations at runtime by tweaking the
429 variable _nc_optimize_enable. See the file include/curses.h.in for
430 mask values, near the end.
432 The Forms and Menu Libraries
434 The forms and menu libraries should work reliably in any environment
435 you can port ncurses to. The only portability issue anywhere in them
436 is what flavor of regular expressions the built-in form field type
437 TYPE_REGEXP will recognize.
439 The configuration code prefers the POSIX regex facility, modeled on
440 System V's, but will settle for BSD regexps if the former isn't
443 Historical note: the panels code was written primarily to assist in
444 porting u386mon 2.0 (comp.sources.misc v14i001-4) to systems lacking
445 panels support; u386mon 2.10 and beyond use it. This version has been
446 slightly cleaned up for ncurses.
448 A Tour of the Terminfo Compiler
450 The ncurses implementation of tic is rather complex internally; it has
451 to do a trying combination of missions. This starts with the fact
452 that, in addition to its normal duty of compiling terminfo sources
453 into loadable terminfo binaries, it has to be able to handle termcap
454 syntax and compile that too into terminfo entries.
456 The implementation therefore starts with a table-driven, dual-mode
457 lexical analyzer (in comp_scan.c). The lexer chooses its mode (termcap
458 or terminfo) based on the first `,' or `:' it finds in each entry. The
459 lexer does all the work of recognizing capability names and values;
460 the grammar above it is trivial, just "parse entries till you run out
463 Translation of Non-use Capabilities
465 Translation of most things besides use capabilities is pretty
466 straightforward. The lexical analyzer's tokenizer hands each
467 capability name to a hash function, which drives a table lookup. The
468 table entry yields an index which is used to look up the token type in
469 another table, and controls interpretation of the value.
471 One possibly interesting aspect of the implementation is the way the
472 compiler tables are initialized. All the tables are generated by
473 various awk/sed/sh scripts from a master table include/Caps; these
474 scripts actually write C initializers which are linked to the
475 compiler. Furthermore, the hash table is generated in the same way, so
476 it doesn't have to be generated at compiler startup time (another
477 benefit of this organization is that the hash table can be in
478 shareable text space).
480 Thus, adding a new capability is usually pretty trivial, just a matter
481 of adding one line to the include/Caps file. We'll have more to say
482 about this in the section on Source-Form Translation.
484 Use Capability Resolution
486 The background problem that makes tic tricky isn't the capability
487 translation itself, it's the resolution of use capabilities. Older
488 versions would not handle forward use references for this reason (that
489 is, a using terminal always had to follow its use target in the source
490 file). By doing this, they got away with a simple implementation
491 tactic; compile everything as it blows by, then resolve uses from
494 This won't do for ncurses. The problem is that that the whole
495 compilation process has to be embeddable in the ncurses library so
496 that it can be called by the startup code to translate termcap entries
497 on the fly. The embedded version can't go promiscuously writing
498 everything it translates out to disk -- for one thing, it will
499 typically be running with non-root permissions.
501 So our tic is designed to parse an entire terminfo file into a
502 doubly-linked circular list of entry structures in-core, and then do
503 use resolution in-memory before writing everything out. This design
504 has other advantages: it makes forward and back use-references equally
505 easy (so we get the latter for free), and it makes checking for name
506 collisions before they're written out easy to do.
508 And this is exactly how the embedded version works. But the
509 stand-alone user-accessible version of tic partly reverts to the
510 historical strategy; it writes to disk (not keeping in core) any entry
511 with no use references.
513 This is strictly a core-economy kluge, implemented because the
514 terminfo master file is large enough that some core-poor systems swap
515 like crazy when you compile it all in memory...there have been reports
516 of this process taking three hours, rather than the twenty seconds or
517 less typical on the author's development box.
519 So. The executable tic passes the entry-parser a hook that immediately
520 writes out the referenced entry if it has no use capabilities. The
521 compiler main loop refrains from adding the entry to the in-core list
522 when this hook fires. If some other entry later needs to reference an
523 entry that got written immediately, that's OK; the resolution code
524 will fetch it off disk when it can't find it in core.
526 Name collisions will still be detected, just not as cleanly. The
527 write_entry() code complains before overwriting an entry that
528 postdates the time of tic's first call to write_entry(), Thus it will
529 complain about overwriting entries newly made during the tic run, but
530 not about overwriting ones that predate it.
532 Source-Form Translation
534 Another use of tic is to do source translation between various termcap
535 and terminfo formats. There are more variants out there than you might
536 think; the ones we know about are described in the captoinfo(1) manual
539 The translation output code (dump_entry() in ncurses/dump_entry.c) is
540 shared with the infocmp(1) utility. It takes the same internal
541 representation used to generate the binary form and dumps it to
542 standard output in a specified format.
544 The include/Caps file has a header comment describing ways you can
545 specify source translations for nonstandard capabilities just by
546 altering the master table. It's possible to set up capability aliasing
547 or tell the compiler to plain ignore a given capability without
548 writing any C code at all.
550 For circumstances where you need to do algorithmic translation, there
551 are functions in parse_entry.c called after the parse of each entry
552 that are specifically intended to encapsulate such translations. This,
553 for example, is where the AIX box1 capability get translated to an
558 The infocmp utility is just a wrapper around the same entry-dumping
559 code used by tic for source translation. Perhaps the one interesting
560 aspect of the code is the use of a predicate function passed in to
561 dump_entry() to control which capabilities are dumped. This is
562 necessary in order to handle both the ordinary De-compilation case and
563 entry difference reporting.
565 The tput and clear utilities just do an entry load followed by a
566 tputs() of a selected capability.
568 Style Tips for Developers
570 See the TO-DO file in the top-level directory of the source
571 distribution for additions that would be particularly useful.
573 The prefix _nc_ should be used on library public functions that are
574 not part of the curses API in order to prevent pollution of the
575 application namespace. If you have to add to or modify the function
576 prototypes in curses.h.in, read ncurses/MKlib_gen.sh first so you can
577 avoid breaking XSI conformance. Please join the ncurses mailing list.
578 See the INSTALL file in the top level of the distribution for details
581 Look for the string FIXME in source files to tag minor bugs and
582 potential problems that could use fixing.
584 Don't try to auto-detect OS features in the main body of the C code.
585 That's the job of the configuration system.
587 To hold down complexity, do make your code data-driven. Especially, if
588 you can drive logic from a table filtered out of include/Caps, do it.
589 If you find you need to augment the data in that file in order to
590 generate the proper table, that's still preferable to ad-hoc code --
591 that's why the fifth field (flags) is there.
597 The following notes are intended to be a first step towards DOS and
598 Macintosh ports of the ncurses libraries.
600 The following library modules are `pure curses'; they operate only on
601 the curses internal structures, do all output through other curses
602 calls (not including tputs() and putp()) and do not call any other
603 UNIX routines such as signal(2) or the stdio library. Thus, they
604 should not need to be modified for single-terminal ports.
606 lib_addch.c lib_addstr.c lib_bkgd.c lib_box.c lib_clear.c lib_clrbot.c
607 lib_clreol.c lib_delch.c lib_delwin.c lib_erase.c lib_inchstr.c
608 lib_insch.c lib_insdel.c lib_insstr.c lib_keyname.c lib_move.c
609 lib_mvwin.c lib_newwin.c lib_overlay.c lib_pad.c lib_printw.c
610 lib_refresh.c lib_scanw.c lib_scroll.c lib_scrreg.c lib_set_term.c
611 lib_touch.c lib_tparm.c lib_tputs.c lib_unctrl.c lib_window.c panel.c
613 This module is pure curses, but calls outstr():
617 These modules are pure curses, except that they use tputs() and
620 lib_beep.c lib_endwin.c lib_color.c lib_options.c lib_slk.c
623 This modules assist in POSIX emulation on non-POSIX systems:
628 The following source files will not be needed for a
629 single-terminal-type port.
631 captoinfo.c clear.c comp_captab.c comp_error.c comp_hash.c comp_main.c
632 comp_parse.c comp_scan.c alloc_entry.c dump_entry.c parse_entry.c
633 read_entry.c write_entry.c infocmp.c tput.c
635 The following modules will use open()/read()/write()/close()/lseek()
636 on files, but no other OS calls.
639 used to read/write screen dumps
642 used to write trace data to the logfile
644 Modules that would have to be modified for a port start here:
646 The following modules are `pure curses' but contain assumptions
647 inappropriate for a memory-mapped port.
649 lib_longname.c -- assumes there may be multiple terminals
650 longname() -- return long name of terminal
651 lib_acs.c -- assumes acs_map as a double indirection
652 init_acs() -- initialize acs map
653 lib_mvcur.c -- assumes cursor moves have variable cost
654 mvcur_init() -- initialize
655 mvcur() -- do physical cursor move
657 scrolln() -- do physical scrolling
658 lib_termcap.c -- assumes there may be multiple terminals
659 tgetent() -- load entry
660 tgetflag() -- get boolean capability
661 tgetnum() -- get numeric capability
662 tgetstr() -- get string capability
663 lib_ti.c -- assumes there may be multiple terminals
664 tigetent() -- load entry
665 tigetflag() -- get boolean capability
666 tigetnum() -- get numeric capability
667 tigetstr() -- get string capability
669 The following modules use UNIX-specific calls:
671 lib_doupdate.c -- input checking
672 doupdate() -- repaint real screen to match virtual
673 _nc_outch() -- put out a single character
674 lib_getch.c -- read()
675 wgetch() -- get single character
676 wungetch() -- push back single character
677 lib_initscr.c -- getenv()
678 initscr() -- initialize curses functions
680 newterm() -- set up new terminal screen
682 baudrate() -- return the baudrate
683 lib_kernel.c -- various tty-manipulation and system calls
684 reset_prog_mode() -- reset ccurses-raw mode
685 reset_shell_mode() -- reset cooked mode
686 erasechar() -- return the erase char
687 killchar() -- return the kill character
688 flushinp() -- flush pending input
689 savetty() -- save tty state
690 resetty() -- reset tty to state at last savetty()
691 lib_raw.c -- various tty-manipulation calls
702 lib_setup.c -- various tty-manipulation calls
705 lib_restart.c -- various tty-manipulation calls
710 lib_tstp.c -- signal-manipulation calls
711 _nc_signal_handler() -- enable/disable window-mode signal catching
712 lib_twait.c -- gettimeofday(), select().
713 usleep() -- microsecond sleep
714 _nc_timed_wait() -- timed wait for input
716 The package kernel could be made smaller.
717 _________________________________________________________________
720 Eric S. Raymond <esr@snark.thyrsus.com>
722 (Note: This is not the bug address!)