1 A Hacker's Guide to NCURSES 2 3 Contents 4 5 * Abstract 6 * Objective of the Package 7 + Why System V Curses? 8 + How to Design Extensions 9 * Portability and Configuration 10 * Documentation Conventions 11 * How to Report Bugs 12 * A Tour of the Ncurses Library 13 + Library Overview 14 + The Engine Room 15 + Keyboard Input 16 + Mouse Events 17 + Output and Screen Updating 18 * The Forms and Menu Libraries 19 * A Tour of the Terminfo Compiler 20 + Translation of Non-use Capabilities 21 + Use Capability Resolution 22 + Source-Form Translation 23 * Other Utilities 24 * Style Tips for Developers 25 * Porting Hints 26 27 Abstract 28 29 This document is a hacker's tour of the ncurses library and utilities. 30 It discusses design philosophy, implementation methods, and the 31 conventions used for coding and documentation. It is recommended 32 reading for anyone who is interested in porting, extending or 33 improving the package. 34 35 Objective of the Package 36 37 The objective of the ncurses package is to provide a free software API 38 for character-cell terminals and terminal emulators with the following 39 characteristics: 40 * Source-compatible with historical curses implementations 41 (including the original BSD curses and System V curses. 42 * Conformant with the XSI Curses standard issued as part of XPG4 by 43 X/Open. 44 * High-quality -- stable and reliable code, wide portability, good 45 packaging, superior documentation. 46 * Featureful -- should eliminate as much of the drudgery of C 47 interface programming as possible, freeing programmers to think at 48 a higher level of design. 49 50 These objectives are in priority order. So, for example, source 51 compatibility with older version must trump featurefulness -- we 52 cannot add features if it means breaking the portion of the API 53 corresponding to historical curses versions. 54 55Why System V Curses? 56 57 We used System V curses as a model, reverse-engineering their API, in 58 order to fulfill the first two objectives. 59 60 System V curses implementations can support BSD curses programs with 61 just a recompilation, so by capturing the System V API we also capture 62 BSD's. 63 64 More importantly for the future, the XSI Curses standard issued by 65 X/Open is explicitly and closely modeled on System V. So conformance 66 with System V took us most of the way to base-level XSI conformance. 67 68How to Design Extensions 69 70 The third objective (standards conformance) requires that it be easy 71 to condition source code using ncurses so that the absence of 72 nonstandard extensions does not break the code. 73 74 Accordingly, we have a policy of associating with each nonstandard 75 extension a feature macro, so that ncurses client code can use this 76 macro to condition in or out the code that requires the ncurses 77 extension. 78 79 For example, there is a macro NCURSES_MOUSE_VERSION which XSI Curses 80 does not define, but which is defined in the ncurses library header. 81 You can use this to condition the calls to the mouse API calls. 82 83 Portability and Configuration 84 85 Code written for ncurses may assume an ANSI-standard C compiler and 86 POSIX-compatible OS interface. It may also assume the presence of a 87 System-V-compatible select(2) call. 88 89 We encourage (but do not require) developers to make the code friendly 90 to less-capable UNIX environments wherever possible. 91 92 We encourage developers to support OS-specific optimizations and 93 methods not available under POSIX/ANSI, provided only that: 94 * All such code is properly conditioned so the build process does 95 not attempt to compile it under a plain ANSI/POSIX environment. 96 * Adding such implementation methods does not introduce 97 incompatibilities in the ncurses API between platforms. 98 99 We use GNU autoconf(1) as a tool to deal with portability issues. The 100 right way to leverage an OS-specific feature is to modify the autoconf 101 specification files (configure.in and aclocal.m4) to set up a new 102 feature macro, which you then use to condition your code. 103 104 Documentation Conventions 105 106 There are three kinds of documentation associated with this package. 107 Each has a different preferred format: 108 * Package-internal files (README, INSTALL, TO-DO etc.) 109 * Manual pages. 110 * Everything else (i.e., narrative documentation). 111 112 Our conventions are simple: 113 1. Maintain package-internal files in plain text. The expected viewer 114 for them more(1) or an editor window; there is no point in 115 elaborate mark-up. 116 2. Mark up manual pages in the man macros. These have to be viewable 117 through traditional man(1) programs. 118 3. Write everything else in HTML. 119 120 When in doubt, HTMLize a master and use lynx(1) to generate plain 121 ASCII (as we do for the announcement document). 122 123 The reason for choosing HTML is that it is (a) well-adapted for 124 on-line browsing through viewers that are everywhere; (b) more easily 125 readable as plain text than most other mark-ups, if you do not have a 126 viewer; and (c) carries enough information that you can generate a 127 nice-looking printed version from it. Also, of course, it make 128 exporting things like the announcement document to WWW pretty trivial. 129 130 How to Report Bugs 131 132 The reporting address for bugs is bug-ncurses@gnu.org. This is a 133 majordomo list; to join, write to bug-ncurses-request@gnu.org with a 134 message containing the line: 135 subscribe <name>@<host.domain> 136 137 The ncurses code is maintained by a small group of volunteers. While 138 we try our best to fix bugs promptly, we simply do not have a lot of 139 hours to spend on elementary hand-holding. We rely on intelligent 140 cooperation from our users. If you think you have found a bug in 141 ncurses, there are some steps you can take before contacting us that 142 will help get the bug fixed quickly. 143 144 In order to use our bug-fixing time efficiently, we put people who 145 show us they have taken these steps at the head of our queue. This 146 means that if you do not, you will probably end up at the tail end and 147 have to wait a while. 148 1. Develop a recipe to reproduce the bug. 149 Bugs we can reproduce are likely to be fixed very quickly, often 150 within days. The most effective single thing you can do to get a 151 quick fix is develop a way we can duplicate the bad behavior -- 152 ideally, by giving us source for a small, portable test program 153 that breaks the library. (Even better is a keystroke recipe using 154 one of the test programs provided with the distribution.) 155 2. Try to reproduce the bug on a different terminal type. 156 In our experience, most of the behaviors people report as library 157 bugs are actually due to subtle problems in terminal descriptions. 158 This is especially likely to be true if you are using a 159 traditional asynchronous terminal or PC-based terminal emulator, 160 rather than xterm or a UNIX console entry. 161 It is therefore extremely helpful if you can tell us whether or 162 not your problem reproduces on other terminal types. Usually you 163 will have both a console type and xterm available; please tell us 164 whether or not your bug reproduces on both. 165 If you have xterm available, it is also good to collect xterm 166 reports for different window sizes. This is especially true if you 167 normally use an unusual xterm window size -- a surprising number 168 of the bugs we have seen are either triggered or masked by these. 169 3. Generate and examine a trace file for the broken behavior. 170 Recompile your program with the debugging versions of the 171 libraries. Insert a trace() call with the argument set to 172 TRACE_UPDATE. (See "Writing Programs with NCURSES" for details on 173 trace levels.) Reproduce your bug, then look at the trace file to 174 see what the library was actually doing. 175 Another frequent cause of apparent bugs is application coding 176 errors that cause the wrong things to be put on the virtual 177 screen. Looking at the virtual-screen dumps in the trace file will 178 tell you immediately if this is happening, and save you from the 179 possible embarrassment of being told that the bug is in your code 180 and is your problem rather than ours. 181 If the virtual-screen dumps look correct but the bug persists, it 182 is possible to crank up the trace level to give more and more 183 information about the library's update actions and the control 184 sequences it issues to perform them. The test directory of the 185 distribution contains a tool for digesting these logs to make them 186 less tedious to wade through. 187 Often you will find terminfo problems at this stage by noticing 188 that the escape sequences put out for various capabilities are 189 wrong. If not, you are likely to learn enough to be able to 190 characterize any bug in the screen-update logic quite exactly. 191 4. Report details and symptoms, not just interpretations. 192 If you do the preceding two steps, it is very likely that you will 193 discover the nature of the problem yourself and be able to send us 194 a fix. This will create happy feelings all around and earn you 195 good karma for the first time you run into a bug you really cannot 196 characterize and fix yourself. 197 If you are still stuck, at least you will know what to tell us. 198 Remember, we need details. If you guess about what is safe to 199 leave out, you are too likely to be wrong. 200 If your bug produces a bad update, include a trace file. Try to 201 make the trace at the least voluminous level that pins down the 202 bug. Logs that have been through tracemunch are OK, it does not 203 throw away any information (actually they are better than 204 un-munched ones because they are easier to read). 205 If your bug produces a core-dump, please include a symbolic stack 206 trace generated by gdb(1) or your local equivalent. 207 Tell us about every terminal on which you have reproduced the bug 208 -- and every terminal on which you cannot. Ideally, send us 209 terminfo sources for all of these (yours might differ from ours). 210 Include your ncurses version and your OS/machine type, of course! 211 You can find your ncurses version in the curses.h file. 212 213 If your problem smells like a logic error or in cursor movement or 214 scrolling or a bad capability, there are a couple of tiny test frames 215 for the library algorithms in the progs directory that may help you 216 isolate it. These are not part of the normal build, but do have their 217 own make productions. 218 219 The most important of these is mvcur, a test frame for the 220 cursor-movement optimization code. With this program, you can see 221 directly what control sequences will be emitted for any given cursor 222 movement or scroll/insert/delete operations. If you think you have got 223 a bad capability identified, you can disable it and test again. The 224 program is command-driven and has on-line help. 225 226 If you think the vertical-scroll optimization is broken, or just want 227 to understand how it works better, build hashmap and read the header 228 comments of hardscroll.c and hashmap.c; then try it out. You can also 229 test the hardware-scrolling optimization separately with hardscroll. 230 231 A Tour of the Ncurses Library 232 233Library Overview 234 235 Most of the library is superstructure -- fairly trivial convenience 236 interfaces to a small set of basic functions and data structures used 237 to manipulate the virtual screen (in particular, none of this code 238 does any I/O except through calls to more fundamental modules 239 described below). The files 240 241 lib_addch.c lib_bkgd.c lib_box.c lib_chgat.c lib_clear.c 242 lib_clearok.c lib_clrbot.c lib_clreol.c lib_colorset.c lib_data.c 243 lib_delch.c lib_delwin.c lib_echo.c lib_erase.c lib_gen.c 244 lib_getstr.c lib_hline.c lib_immedok.c lib_inchstr.c lib_insch.c 245 lib_insdel.c lib_insstr.c lib_instr.c lib_isendwin.c lib_keyname.c 246 lib_leaveok.c lib_move.c lib_mvwin.c lib_overlay.c lib_pad.c 247 lib_printw.c lib_redrawln.c lib_scanw.c lib_screen.c lib_scroll.c 248 lib_scrollok.c lib_scrreg.c lib_set_term.c lib_slk.c 249 lib_slkatr_set.c lib_slkatrof.c lib_slkatron.c lib_slkatrset.c 250 lib_slkattr.c lib_slkclear.c lib_slkcolor.c lib_slkinit.c 251 lib_slklab.c lib_slkrefr.c lib_slkset.c lib_slktouch.c lib_touch.c 252 lib_unctrl.c lib_vline.c lib_wattroff.c lib_wattron.c lib_window.c 253 254 are all in this category. They are very unlikely to need change, 255 barring bugs or some fundamental reorganization in the underlying data 256 structures. 257 258 These files are used only for debugging support: 259 260 lib_trace.c lib_traceatr.c lib_tracebits.c lib_tracechr.c 261 lib_tracedmp.c lib_tracemse.c trace_buf.c 262 263 It is rather unlikely you will ever need to change these, unless you 264 want to introduce a new debug trace level for some reason. 265 266 There is another group of files that do direct I/O via tputs(), 267 computations on the terminal capabilities, or queries to the OS 268 environment, but nevertheless have only fairly low complexity. These 269 include: 270 271 lib_acs.c lib_beep.c lib_color.c lib_endwin.c lib_initscr.c 272 lib_longname.c lib_newterm.c lib_options.c lib_termcap.c lib_ti.c 273 lib_tparm.c lib_tputs.c lib_vidattr.c read_entry.c. 274 275 They are likely to need revision only if ncurses is being ported to an 276 environment without an underlying terminfo capability representation. 277 278 These files have serious hooks into the tty driver and signal 279 facilities: 280 281 lib_kernel.c lib_baudrate.c lib_raw.c lib_tstp.c lib_twait.c 282 283 If you run into porting snafus moving the package to another UNIX, the 284 problem is likely to be in one of these files. The file lib_print.c 285 uses sleep(2) and also falls in this category. 286 287 Almost all of the real work is done in the files 288 289 hardscroll.c hashmap.c lib_addch.c lib_doupdate.c lib_getch.c 290 lib_mouse.c lib_mvcur.c lib_refresh.c lib_setup.c lib_vidattr.c 291 292 Most of the algorithmic complexity in the library lives in these 293 files. If there is a real bug in ncurses itself, it is probably here. 294 We will tour some of these files in detail below (see The Engine 295 Room). 296 297 Finally, there is a group of files that is actually most of the 298 terminfo compiler. The reason this code lives in the ncurses library 299 is to support fallback to /etc/termcap. These files include 300 301 alloc_entry.c captoinfo.c comp_captab.c comp_error.c comp_hash.c 302 comp_parse.c comp_scan.c parse_entry.c read_termcap.c write_entry.c 303 304 We will discuss these in the compiler tour. 305 306The Engine Room 307 308 Keyboard Input 309 310 All ncurses input funnels through the function wgetch(), defined in 311 lib_getch.c. This function is tricky; it has to poll for keyboard and 312 mouse events and do a running match of incoming input against the set 313 of defined special keys. 314 315 The central data structure in this module is a FIFO queue, used to 316 match multiple-character input sequences against special-key 317 capabilities; also to implement pushback via ungetch(). 318 319 The wgetch() code distinguishes between function key sequences and the 320 same sequences typed manually by doing a timed wait after each input 321 character that could lead a function key sequence. If the entire 322 sequence takes less than 1 second, it is assumed to have been 323 generated by a function key press. 324 325 Hackers bruised by previous encounters with variant select(2) calls 326 may find the code in lib_twait.c interesting. It deals with the 327 problem that some BSD selects do not return a reliable time-left 328 value. The function timed_wait() effectively simulates a System V 329 select. 330 331 Mouse Events 332 333 If the mouse interface is active, wgetch() polls for mouse events each 334 call, before it goes to the keyboard for input. It is up to 335 lib_mouse.c how the polling is accomplished; it may vary for different 336 devices. 337 338 Under xterm, however, mouse event notifications come in via the 339 keyboard input stream. They are recognized by having the kmous 340 capability as a prefix. This is kind of klugey, but trying to wire in 341 recognition of a mouse key prefix without going through the 342 function-key machinery would be just too painful, and this turns out 343 to imply having the prefix somewhere in the function-key capabilities 344 at terminal-type initialization. 345 346 This kluge only works because kmous is not actually used by any 347 historic terminal type or curses implementation we know of. Best guess 348 is it is a relic of some forgotten experiment in-house at Bell Labs 349 that did not leave any traces in the publicly-distributed System V 350 terminfo files. If System V or XPG4 ever gets serious about using it 351 again, this kluge may have to change. 352 353 Here are some more details about mouse event handling: 354 355 The lib_mouse() code is logically split into a lower level that 356 accepts event reports in a device-dependent format and an upper level 357 that parses mouse gestures and filters events. The mediating data 358 structure is a circular queue of event structures. 359 360 Functionally, the lower level's job is to pick up primitive events and 361 put them on the circular queue. This can happen in one of two ways: 362 either (a) _nc_mouse_event() detects a series of incoming mouse 363 reports and queues them, or (b) code in lib_getch.c detects the kmous 364 prefix in the keyboard input stream and calls _nc_mouse_inline to 365 queue up a series of adjacent mouse reports. 366 367 In either case, _nc_mouse_parse() should be called after the series is 368 accepted to parse the digested mouse reports (low-level events) into a 369 gesture (a high-level or composite event). 370 371 Output and Screen Updating 372 373 With the single exception of character echoes during a wgetnstr() call 374 (which simulates cooked-mode line editing in an ncurses window), the 375 library normally does all its output at refresh time. 376 377 The main job is to go from the current state of the screen (as 378 represented in the curscr window structure) to the desired new state 379 (as represented in the newscr window structure), while doing as little 380 I/O as possible. 381 382 The brains of this operation are the modules hashmap.c, hardscroll.c 383 and lib_doupdate.c; the latter two use lib_mvcur.c. Essentially, what 384 happens looks like this: 385 * The hashmap.c module tries to detect vertical motion changes 386 between the real and virtual screens. This information is 387 represented by the oldindex members in the newscr structure. These 388 are modified by vertical-motion and clear operations, and both are 389 re-initialized after each update. To this change-journalling 390 information, the hashmap code adds deductions made using a 391 modified Heckel algorithm on hash values generated from the line 392 contents. 393 * The hardscroll.c module computes an optimum set of scroll, 394 insertion, and deletion operations to make the indices match. It 395 calls _nc_mvcur_scrolln() in lib_mvcur.c to do those motions. 396 * Then lib_doupdate.c goes to work. Its job is to do line-by-line 397 transformations of curscr lines to newscr lines. Its main tool is 398 the routine mvcur() in lib_mvcur.c. This routine does 399 cursor-movement optimization, attempting to get from given screen 400 location A to given location B in the fewest output characters 401 possible. 402 403 If you want to work on screen optimizations, you should use the fact 404 that (in the trace-enabled version of the library) enabling the 405 TRACE_TIMES trace level causes a report to be emitted after each 406 screen update giving the elapsed time and a count of characters 407 emitted during the update. You can use this to tell when an update 408 optimization improves efficiency. 409 410 In the trace-enabled version of the library, it is also possible to 411 disable and re-enable various optimizations at runtime by tweaking the 412 variable _nc_optimize_enable. See the file include/curses.h.in for 413 mask values, near the end. 414 415 The Forms and Menu Libraries 416 417 The forms and menu libraries should work reliably in any environment 418 you can port ncurses to. The only portability issue anywhere in them 419 is what flavor of regular expressions the built-in form field type 420 TYPE_REGEXP will recognize. 421 422 The configuration code prefers the POSIX regex facility, modeled on 423 System V's, but will settle for BSD regexps if the former is not 424 available. 425 426 Historical note: the panels code was written primarily to assist in 427 porting u386mon 2.0 (comp.sources.misc v14i001-4) to systems lacking 428 panels support; u386mon 2.10 and beyond use it. This version has been 429 slightly cleaned up for ncurses. 430 431 A Tour of the Terminfo Compiler 432 433 The ncurses implementation of tic is rather complex internally; it has 434 to do a trying combination of missions. This starts with the fact 435 that, in addition to its normal duty of compiling terminfo sources 436 into loadable terminfo binaries, it has to be able to handle termcap 437 syntax and compile that too into terminfo entries. 438 439 The implementation therefore starts with a table-driven, dual-mode 440 lexical analyzer (in comp_scan.c). The lexer chooses its mode (termcap 441 or terminfo) based on the first "," or ":" it finds in each entry. The 442 lexer does all the work of recognizing capability names and values; 443 the grammar above it is trivial, just "parse entries till you run out 444 of file". 445 446Translation of Non-use Capabilities 447 448 Translation of most things besides use capabilities is pretty 449 straightforward. The lexical analyzer's tokenizer hands each 450 capability name to a hash function, which drives a table lookup. The 451 table entry yields an index which is used to look up the token type in 452 another table, and controls interpretation of the value. 453 454 One possibly interesting aspect of the implementation is the way the 455 compiler tables are initialized. All the tables are generated by 456 various awk/sed/sh scripts from a master table include/Caps; these 457 scripts actually write C initializers which are linked to the 458 compiler. Furthermore, the hash table is generated in the same way, so 459 it doesn't have to be generated at compiler startup time (another 460 benefit of this organization is that the hash table can be in 461 shareable text space). 462 463 Thus, adding a new capability is usually pretty trivial, just a matter 464 of adding one line to the include/Caps file. We will have more to say 465 about this in the section on Source-Form Translation. 466 467Use Capability Resolution 468 469 The background problem that makes tic tricky is not the capability 470 translation itself, it is the resolution of use capabilities. Older 471 versions would not handle forward use references for this reason (that 472 is, a using terminal always had to follow its use target in the source 473 file). By doing this, they got away with a simple implementation 474 tactic; compile everything as it blows by, then resolve uses from 475 compiled entries. 476 477 This will not do for ncurses. The problem is that that the whole 478 compilation process has to be embeddable in the ncurses library so 479 that it can be called by the startup code to translate termcap entries 480 on the fly. The embedded version cannot go promiscuously writing 481 everything it translates out to disk -- for one thing, it will 482 typically be running with non-root permissions. 483 484 So our tic is designed to parse an entire terminfo file into a 485 doubly-linked circular list of entry structures in-core, and then do 486 use resolution in-memory before writing everything out. This design 487 has other advantages: it makes forward and back use-references equally 488 easy (so we get the latter for free), and it makes checking for name 489 collisions before they are written out easy to do. 490 491 And this is exactly how the embedded version works. But the 492 stand-alone user-accessible version of tic partly reverts to the 493 historical strategy; it writes to disk (not keeping in core) any entry 494 with no use references. 495 496 This is strictly a core-economy kluge, implemented because the 497 terminfo master file is large enough that some core-poor systems swap 498 like crazy when you compile it all in memory...there have been reports 499 of this process taking three hours, rather than the twenty seconds or 500 less typical on the author's development box. 501 502 So. The executable tic passes the entry-parser a hook that immediately 503 writes out the referenced entry if it has no use capabilities. The 504 compiler main loop refrains from adding the entry to the in-core list 505 when this hook fires. If some other entry later needs to reference an 506 entry that got written immediately, that is OK; the resolution code 507 will fetch it off disk when it cannot find it in core. 508 509 Name collisions will still be detected, just not as cleanly. The 510 write_entry() code complains before overwriting an entry that 511 postdates the time of tic's first call to write_entry(), Thus it will 512 complain about overwriting entries newly made during the tic run, but 513 not about overwriting ones that predate it. 514 515Source-Form Translation 516 517 Another use of tic is to do source translation between various termcap 518 and terminfo formats. There are more variants out there than you might 519 think; the ones we know about are described in the captoinfo(1) manual 520 page. 521 522 The translation output code (dump_entry() in ncurses/dump_entry.c) is 523 shared with the infocmp(1) utility. It takes the same internal 524 representation used to generate the binary form and dumps it to 525 standard output in a specified format. 526 527 The include/Caps file has a header comment describing ways you can 528 specify source translations for nonstandard capabilities just by 529 altering the master table. It is possible to set up capability 530 aliasing or tell the compiler to plain ignore a given capability 531 without writing any C code at all. 532 533 For circumstances where you need to do algorithmic translation, there 534 are functions in parse_entry.c called after the parse of each entry 535 that are specifically intended to encapsulate such translations. This, 536 for example, is where the AIX box1 capability get translated to an 537 acsc string. 538 539 Other Utilities 540 541 The infocmp utility is just a wrapper around the same entry-dumping 542 code used by tic for source translation. Perhaps the one interesting 543 aspect of the code is the use of a predicate function passed in to 544 dump_entry() to control which capabilities are dumped. This is 545 necessary in order to handle both the ordinary De-compilation case and 546 entry difference reporting. 547 548 The tput and clear utilities just do an entry load followed by a 549 tputs() of a selected capability. 550 551 Style Tips for Developers 552 553 See the TO-DO file in the top-level directory of the source 554 distribution for additions that would be particularly useful. 555 556 The prefix _nc_ should be used on library public functions that are 557 not part of the curses API in order to prevent pollution of the 558 application namespace. If you have to add to or modify the function 559 prototypes in curses.h.in, read ncurses/MKlib_gen.sh first so you can 560 avoid breaking XSI conformance. Please join the ncurses mailing list. 561 See the INSTALL file in the top level of the distribution for details 562 on the list. 563 564 Look for the string FIXME in source files to tag minor bugs and 565 potential problems that could use fixing. 566 567 Do not try to auto-detect OS features in the main body of the C code. 568 That is the job of the configuration system. 569 570 To hold down complexity, do make your code data-driven. Especially, if 571 you can drive logic from a table filtered out of include/Caps, do it. 572 If you find you need to augment the data in that file in order to 573 generate the proper table, that is still preferable to ad-hoc code -- 574 that is why the fifth field (flags) is there. 575 576 Have fun! 577 578 Porting Hints 579 580 The following notes are intended to be a first step towards DOS and 581 Macintosh ports of the ncurses libraries. 582 583 The following library modules are "pure curses"; they operate only on 584 the curses internal structures, do all output through other curses 585 calls (not including tputs() and putp()) and do not call any other 586 UNIX routines such as signal(2) or the stdio library. Thus, they 587 should not need to be modified for single-terminal ports. 588 589 lib_addch.c lib_addstr.c lib_bkgd.c lib_box.c lib_clear.c 590 lib_clrbot.c lib_clreol.c lib_delch.c lib_delwin.c lib_erase.c 591 lib_inchstr.c lib_insch.c lib_insdel.c lib_insstr.c lib_keyname.c 592 lib_move.c lib_mvwin.c lib_newwin.c lib_overlay.c lib_pad.c 593 lib_printw.c lib_refresh.c lib_scanw.c lib_scroll.c lib_scrreg.c 594 lib_set_term.c lib_touch.c lib_tparm.c lib_tputs.c lib_unctrl.c 595 lib_window.c panel.c 596 597 This module is pure curses, but calls outstr(): 598 599 lib_getstr.c 600 601 These modules are pure curses, except that they use tputs() and 602 putp(): 603 604 lib_beep.c lib_color.c lib_endwin.c lib_options.c lib_slk.c 605 lib_vidattr.c 606 607 This modules assist in POSIX emulation on non-POSIX systems: 608 609 sigaction.c 610 signal calls 611 612 The following source files will not be needed for a 613 single-terminal-type port. 614 615 alloc_entry.c captoinfo.c clear.c comp_captab.c comp_error.c 616 comp_hash.c comp_main.c comp_parse.c comp_scan.c dump_entry.c 617 infocmp.c parse_entry.c read_entry.c tput.c write_entry.c 618 619 The following modules will use open()/read()/write()/close()/lseek() 620 on files, but no other OS calls. 621 622 lib_screen.c 623 used to read/write screen dumps 624 625 lib_trace.c 626 used to write trace data to the logfile 627 628 Modules that would have to be modified for a port start here: 629 630 The following modules are "pure curses" but contain assumptions 631 inappropriate for a memory-mapped port. 632 633 lib_longname.c 634 assumes there may be multiple terminals 635 636 lib_acs.c 637 assumes acs_map as a double indirection 638 639 lib_mvcur.c 640 assumes cursor moves have variable cost 641 642 lib_termcap.c 643 assumes there may be multiple terminals 644 645 lib_ti.c 646 assumes there may be multiple terminals 647 648 The following modules use UNIX-specific calls: 649 650 lib_doupdate.c 651 input checking 652 653 lib_getch.c 654 read() 655 656 lib_initscr.c 657 getenv() 658 659 lib_newterm.c 660 lib_baudrate.c 661 lib_kernel.c 662 various tty-manipulation and system calls 663 664 lib_raw.c 665 various tty-manipulation calls 666 667 lib_setup.c 668 various tty-manipulation calls 669 670 lib_restart.c 671 various tty-manipulation calls 672 673 lib_tstp.c 674 signal-manipulation calls 675 676 lib_twait.c 677 gettimeofday(), select(). 678 _________________________________________________________________ 679 680 681 Eric S. Raymond <esr@snark.thyrsus.com> 682 683 (Note: This is not the bug address!) 684