1 A Hacker's Guide to NCURSES 2 3A Hacker's Guide to NCURSES 4 5Contents 6 7 * Abstract 8 * Objective of the Package 9 + Why System V Curses? 10 + How to Design Extensions 11 * Portability and Configuration 12 * Documentation Conventions 13 * How to Report Bugs 14 * A Tour of the Ncurses Library 15 + Library Overview 16 + The Engine Room 17 + Keyboard Input 18 + Mouse Events 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 25 * Other Utilities 26 * Style Tips for Developers 27 * Porting Hints 28 29Abstract 30 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. 36 37Objective of the Package 38 39 The objective of the ncurses package is to provide a free software API 40 for character-cell terminals and terminal emulators with the following 41 characteristics: 42 * Source-compatible with historical curses implementations 43 (including the original BSD curses and System V curses. 44 * Conformant with the XSI Curses standard issued as part of XPG4 by 45 X/Open. 46 * High-quality -- stable and reliable code, wide portability, good 47 packaging, superior documentation. 48 * Featureful -- should eliminate as much of the drudgery of C 49 interface programming as possible, freeing programmers to think at 50 a higher level of design. 51 52 These objectives are in priority order. So, for example, source 53 compatibility with older version must trump featurefulness -- we 54 cannot add features if it means breaking the portion of the API 55 corresponding to historical curses versions. 56 57 Why System V Curses? 58 59 We used System V curses as a model, reverse-engineering their API, in 60 order to fulfill the first two objectives. 61 62 System V curses implementations can support BSD curses programs with 63 just a recompilation, so by capturing the System V API we also capture 64 BSD's. 65 66 More importantly for the future, the XSI Curses standard issued by 67 X/Open is explicitly and closely modeled on System V. So conformance 68 with System V took us most of the way to base-level XSI conformance. 69 70 How to Design Extensions 71 72 The third objective (standards conformance) requires that it be easy 73 to condition source code using ncurses so that the absence of 74 nonstandard extensions does not break the code. 75 76 Accordingly, we have a policy of associating with each nonstandard 77 extension a feature macro, so that ncurses client code can use this 78 macro to condition in or out the code that requires the ncurses 79 extension. 80 81 For example, there is a macro NCURSES_MOUSE_VERSION which XSI Curses 82 does not define, but which is defined in the ncurses library header. 83 You can use this to condition the calls to the mouse API calls. 84 85Portability and Configuration 86 87 Code written for ncurses may assume an ANSI-standard C compiler and 88 POSIX-compatible OS interface. It may also assume the presence of a 89 System-V-compatible select(2) call. 90 91 We encourage (but do not require) developers to make the code friendly 92 to less-capable UNIX environments wherever possible. 93 94 We encourage developers to support OS-specific optimizations and 95 methods not available under POSIX/ANSI, provided only that: 96 * All such code is properly conditioned so the build process does 97 not attempt to compile it under a plain ANSI/POSIX environment. 98 * Adding such implementation methods does not introduce 99 incompatibilities in the ncurses API between platforms. 100 101 We use GNU autoconf(1) as a tool to deal with portability issues. The 102 right way to leverage an OS-specific feature is to modify the autoconf 103 specification files (configure.in and aclocal.m4) to set up a new 104 feature macro, which you then use to condition your code. 105 106Documentation Conventions 107 108 There are three kinds of documentation associated with this package. 109 Each has a different preferred format: 110 * Package-internal files (README, INSTALL, TO-DO etc.) 111 * Manual pages. 112 * Everything else (i.e., narrative documentation). 113 114 Our conventions are simple: 115 1. Maintain package-internal files in plain text. The expected viewer 116 for them is more(1) or an editor window; there is no point in 117 elaborate mark-up. 118 2. Mark up manual pages in the man macros. These have to be viewable 119 through traditional man(1) programs. 120 3. Write everything else in HTML. 121 122 When in doubt, HTMLize a master and use lynx(1) to generate plain 123 ASCII (as we do for the announcement document). 124 125 The reason for choosing HTML is that it is (a) well-adapted for 126 on-line browsing through viewers that are everywhere; (b) more easily 127 readable as plain text than most other mark-ups, if you do not have a 128 viewer; and (c) carries enough information that you can generate a 129 nice-looking printed version from it. Also, of course, it make 130 exporting things like the announcement document to WWW pretty trivial. 131 132How to Report Bugs 133 134 The reporting address for bugs is bug-ncurses@gnu.org. This is a 135 majordomo list; to join, write to bug-ncurses-request@gnu.org with a 136 message containing the line: 137 subscribe <name>@<host.domain> 138 139 The ncurses code is maintained by a small group of volunteers. While 140 we try our best to fix bugs promptly, we simply do not have a lot of 141 hours to spend on elementary hand-holding. We rely on intelligent 142 cooperation from our users. If you think you have found a bug in 143 ncurses, there are some steps you can take before contacting us that 144 will help get the bug fixed quickly. 145 146 In order to use our bug-fixing time efficiently, we put people who 147 show us they have taken these steps at the head of our queue. This 148 means that if you do not, you will probably end up at the tail end and 149 have to wait a while. 150 1. Develop a recipe to reproduce the bug. 151 Bugs we can reproduce are likely to be fixed very quickly, often 152 within days. The most effective single thing you can do to get a 153 quick fix is develop a way we can duplicate the bad behavior -- 154 ideally, by giving us source for a small, portable test program 155 that breaks the library. (Even better is a keystroke recipe using 156 one of the test programs provided with the distribution.) 157 2. Try to reproduce the bug on a different terminal type. 158 In our experience, most of the behaviors people report as library 159 bugs are actually due to subtle problems in terminal descriptions. 160 This is especially likely to be true if you are using a 161 traditional asynchronous terminal or PC-based terminal emulator, 162 rather than xterm or a UNIX console entry. 163 It is therefore extremely helpful if you can tell us whether or 164 not your problem reproduces on other terminal types. Usually you 165 will have both a console type and xterm available; please tell us 166 whether or not your bug reproduces on both. 167 If you have xterm available, it is also good to collect xterm 168 reports for different window sizes. This is especially true if you 169 normally use an unusual xterm window size -- a surprising number 170 of the bugs we have seen are either triggered or masked by these. 171 3. Generate and examine a trace file for the broken behavior. 172 Recompile your program with the debugging versions of the 173 libraries. Insert a trace() call with the argument set to 174 TRACE_UPDATE. (See "Writing Programs with NCURSES" for details on 175 trace levels.) Reproduce your bug, then look at the trace file to 176 see what the library was actually doing. 177 Another frequent cause of apparent bugs is application coding 178 errors that cause the wrong things to be put on the virtual 179 screen. Looking at the virtual-screen dumps in the trace file will 180 tell you immediately if this is happening, and save you from the 181 possible embarrassment of being told that the bug is in your code 182 and is your problem rather than ours. 183 If the virtual-screen dumps look correct but the bug persists, it 184 is possible to crank up the trace level to give more and more 185 information about the library's update actions and the control 186 sequences it issues to perform them. The test directory of the 187 distribution contains a tool for digesting these logs to make them 188 less tedious to wade through. 189 Often you will find terminfo problems at this stage by noticing 190 that the escape sequences put out for various capabilities are 191 wrong. If not, you are likely to learn enough to be able to 192 characterize any bug in the screen-update logic quite exactly. 193 4. Report details and symptoms, not just interpretations. 194 If you do the preceding two steps, it is very likely that you will 195 discover the nature of the problem yourself and be able to send us 196 a fix. This will create happy feelings all around and earn you 197 good karma for the first time you run into a bug you really cannot 198 characterize and fix yourself. 199 If you are still stuck, at least you will know what to tell us. 200 Remember, we need details. If you guess about what is safe to 201 leave out, you are too likely to be wrong. 202 If your bug produces a bad update, include a trace file. Try to 203 make the trace at the least voluminous level that pins down the 204 bug. Logs that have been through tracemunch are OK, it does not 205 throw away any information (actually they are better than 206 un-munched ones because they are easier to read). 207 If your bug produces a core-dump, please include a symbolic stack 208 trace generated by gdb(1) or your local equivalent. 209 Tell us about every terminal on which you have reproduced the bug 210 -- and every terminal on which you cannot. Ideally, send us 211 terminfo sources for all of these (yours might differ from ours). 212 Include your ncurses version and your OS/machine type, of course! 213 You can find your ncurses version in the curses.h file. 214 215 If your problem smells like a logic error or in cursor movement or 216 scrolling or a bad capability, there are a couple of tiny test frames 217 for the library algorithms in the progs directory that may help you 218 isolate it. These are not part of the normal build, but do have their 219 own make productions. 220 221 The most important of these is mvcur, a test frame for the 222 cursor-movement optimization code. With this program, you can see 223 directly what control sequences will be emitted for any given cursor 224 movement or scroll/insert/delete operations. If you think you have got 225 a bad capability identified, you can disable it and test again. The 226 program is command-driven and has on-line help. 227 228 If you think the vertical-scroll optimization is broken, or just want 229 to understand how it works better, build hashmap and read the header 230 comments of hardscroll.c and hashmap.c; then try it out. You can also 231 test the hardware-scrolling optimization separately with hardscroll. 232 233A Tour of the Ncurses Library 234 235 Library Overview 236 237 Most of the library is superstructure -- fairly trivial convenience 238 interfaces to a small set of basic functions and data structures used 239 to manipulate the virtual screen (in particular, none of this code 240 does any I/O except through calls to more fundamental modules 241 described below). The files 242 243 lib_addch.c lib_bkgd.c lib_box.c lib_chgat.c lib_clear.c 244 lib_clearok.c lib_clrbot.c lib_clreol.c lib_colorset.c lib_data.c 245 lib_delch.c lib_delwin.c lib_echo.c lib_erase.c lib_gen.c 246 lib_getstr.c lib_hline.c lib_immedok.c lib_inchstr.c lib_insch.c 247 lib_insdel.c lib_insstr.c lib_instr.c lib_isendwin.c lib_keyname.c 248 lib_leaveok.c lib_move.c lib_mvwin.c lib_overlay.c lib_pad.c 249 lib_printw.c lib_redrawln.c lib_scanw.c lib_screen.c lib_scroll.c 250 lib_scrollok.c lib_scrreg.c lib_set_term.c lib_slk.c 251 lib_slkatr_set.c lib_slkatrof.c lib_slkatron.c lib_slkatrset.c 252 lib_slkattr.c lib_slkclear.c lib_slkcolor.c lib_slkinit.c 253 lib_slklab.c lib_slkrefr.c lib_slkset.c lib_slktouch.c lib_touch.c 254 lib_unctrl.c lib_vline.c lib_wattroff.c lib_wattron.c lib_window.c 255 256 are all in this category. They are very unlikely to need change, 257 barring bugs or some fundamental reorganization in the underlying data 258 structures. 259 260 These files are used only for debugging support: 261 262 lib_trace.c lib_traceatr.c lib_tracebits.c lib_tracechr.c 263 lib_tracedmp.c lib_tracemse.c trace_buf.c 264 265 It is rather unlikely you will ever need to change these, unless you 266 want to introduce a new debug trace level for some reason. 267 268 There is another group of files that do direct I/O via tputs(), 269 computations on the terminal capabilities, or queries to the OS 270 environment, but nevertheless have only fairly low complexity. These 271 include: 272 273 lib_acs.c lib_beep.c lib_color.c lib_endwin.c lib_initscr.c 274 lib_longname.c lib_newterm.c lib_options.c lib_termcap.c lib_ti.c 275 lib_tparm.c lib_tputs.c lib_vidattr.c read_entry.c. 276 277 They are likely to need revision only if ncurses is being ported to an 278 environment without an underlying terminfo capability representation. 279 280 These files have serious hooks into the tty driver and signal 281 facilities: 282 283 lib_kernel.c lib_baudrate.c lib_raw.c lib_tstp.c lib_twait.c 284 285 If you run into porting snafus moving the package to another UNIX, the 286 problem is likely to be in one of these files. The file lib_print.c 287 uses sleep(2) and also falls in this category. 288 289 Almost all of the real work is done in the files 290 291 hardscroll.c hashmap.c lib_addch.c lib_doupdate.c lib_getch.c 292 lib_mouse.c lib_mvcur.c lib_refresh.c lib_setup.c lib_vidattr.c 293 294 Most of the algorithmic complexity in the library lives in these 295 files. If there is a real bug in ncurses itself, it is probably here. 296 We will tour some of these files in detail below (see The Engine 297 Room). 298 299 Finally, there is a group of files that is actually most of the 300 terminfo compiler. The reason this code lives in the ncurses library 301 is to support fallback to /etc/termcap. These files include 302 303 alloc_entry.c captoinfo.c comp_captab.c comp_error.c comp_hash.c 304 comp_parse.c comp_scan.c parse_entry.c read_termcap.c write_entry.c 305 306 We will discuss these in the compiler tour. 307 308 The Engine Room 309 310 Keyboard Input 311 312 All ncurses input funnels through the function wgetch(), defined in 313 lib_getch.c. This function is tricky; it has to poll for keyboard and 314 mouse events and do a running match of incoming input against the set 315 of defined special keys. 316 317 The central data structure in this module is a FIFO queue, used to 318 match multiple-character input sequences against special-key 319 capabilities; also to implement pushback via ungetch(). 320 321 The wgetch() code distinguishes between function key sequences and the 322 same sequences typed manually by doing a timed wait after each input 323 character that could lead a function key sequence. If the entire 324 sequence takes less than 1 second, it is assumed to have been 325 generated by a function key press. 326 327 Hackers bruised by previous encounters with variant select(2) calls 328 may find the code in lib_twait.c interesting. It deals with the 329 problem that some BSD selects do not return a reliable time-left 330 value. The function timed_wait() effectively simulates a System V 331 select. 332 333 Mouse Events 334 335 If the mouse interface is active, wgetch() polls for mouse events each 336 call, before it goes to the keyboard for input. It is up to 337 lib_mouse.c how the polling is accomplished; it may vary for different 338 devices. 339 340 Under xterm, however, mouse event notifications come in via the 341 keyboard input stream. They are recognized by having the kmous 342 capability as a prefix. This is kind of klugey, but trying to wire in 343 recognition of a mouse key prefix without going through the 344 function-key machinery would be just too painful, and this turns out 345 to imply having the prefix somewhere in the function-key capabilities 346 at terminal-type initialization. 347 348 This kluge only works because kmous is not actually used by any 349 historic terminal type or curses implementation we know of. Best guess 350 is it is a relic of some forgotten experiment in-house at Bell Labs 351 that did not leave any traces in the publicly-distributed System V 352 terminfo files. If System V or XPG4 ever gets serious about using it 353 again, this kluge may have to change. 354 355 Here are some more details about mouse event handling: 356 357 The lib_mouse() code is logically split into a lower level that 358 accepts event reports in a device-dependent format and an upper level 359 that parses mouse gestures and filters events. The mediating data 360 structure is a circular queue of event structures. 361 362 Functionally, the lower level's job is to pick up primitive events and 363 put them on the circular queue. This can happen in one of two ways: 364 either (a) _nc_mouse_event() detects a series of incoming mouse 365 reports and queues them, or (b) code in lib_getch.c detects the kmous 366 prefix in the keyboard input stream and calls _nc_mouse_inline to 367 queue up a series of adjacent mouse reports. 368 369 In either case, _nc_mouse_parse() should be called after the series is 370 accepted to parse the digested mouse reports (low-level events) into a 371 gesture (a high-level or composite event). 372 373 Output and Screen Updating 374 375 With the single exception of character echoes during a wgetnstr() call 376 (which simulates cooked-mode line editing in an ncurses window), the 377 library normally does all its output at refresh time. 378 379 The main job is to go from the current state of the screen (as 380 represented in the curscr window structure) to the desired new state 381 (as represented in the newscr window structure), while doing as little 382 I/O as possible. 383 384 The brains of this operation are the modules hashmap.c, hardscroll.c 385 and lib_doupdate.c; the latter two use lib_mvcur.c. Essentially, what 386 happens looks like this: 387 * The hashmap.c module tries to detect vertical motion changes 388 between the real and virtual screens. This information is 389 represented by the oldindex members in the newscr structure. These 390 are modified by vertical-motion and clear operations, and both are 391 re-initialized after each update. To this change-journalling 392 information, the hashmap code adds deductions made using a 393 modified Heckel algorithm on hash values generated from the line 394 contents. 395 * The hardscroll.c module computes an optimum set of scroll, 396 insertion, and deletion operations to make the indices match. It 397 calls _nc_mvcur_scrolln() in lib_mvcur.c to do those motions. 398 * Then lib_doupdate.c goes to work. Its job is to do line-by-line 399 transformations of curscr lines to newscr lines. Its main tool is 400 the routine mvcur() in lib_mvcur.c. This routine does 401 cursor-movement optimization, attempting to get from given screen 402 location A to given location B in the fewest output characters 403 possible. 404 405 If you want to work on screen optimizations, you should use the fact 406 that (in the trace-enabled version of the library) enabling the 407 TRACE_TIMES trace level causes a report to be emitted after each 408 screen update giving the elapsed time and a count of characters 409 emitted during the update. You can use this to tell when an update 410 optimization improves efficiency. 411 412 In the trace-enabled version of the library, it is also possible to 413 disable and re-enable various optimizations at runtime by tweaking the 414 variable _nc_optimize_enable. See the file include/curses.h.in for 415 mask values, near the end. 416 417The Forms and Menu Libraries 418 419 The forms and menu libraries should work reliably in any environment 420 you can port ncurses to. The only portability issue anywhere in them 421 is what flavor of regular expressions the built-in form field type 422 TYPE_REGEXP will recognize. 423 424 The configuration code prefers the POSIX regex facility, modeled on 425 System V's, but will settle for BSD regexps if the former is not 426 available. 427 428 Historical note: the panels code was written primarily to assist in 429 porting u386mon 2.0 (comp.sources.misc v14i001-4) to systems lacking 430 panels support; u386mon 2.10 and beyond use it. This version has been 431 slightly cleaned up for ncurses. 432 433A Tour of the Terminfo Compiler 434 435 The ncurses implementation of tic is rather complex internally; it has 436 to do a trying combination of missions. This starts with the fact 437 that, in addition to its normal duty of compiling terminfo sources 438 into loadable terminfo binaries, it has to be able to handle termcap 439 syntax and compile that too into terminfo entries. 440 441 The implementation therefore starts with a table-driven, dual-mode 442 lexical analyzer (in comp_scan.c). The lexer chooses its mode (termcap 443 or terminfo) based on the first "," or ":" it finds in each entry. The 444 lexer does all the work of recognizing capability names and values; 445 the grammar above it is trivial, just "parse entries till you run out 446 of file". 447 448 Translation of Non-use Capabilities 449 450 Translation of most things besides use capabilities is pretty 451 straightforward. The lexical analyzer's tokenizer hands each 452 capability name to a hash function, which drives a table lookup. The 453 table entry yields an index which is used to look up the token type in 454 another table, and controls interpretation of the value. 455 456 One possibly interesting aspect of the implementation is the way the 457 compiler tables are initialized. All the tables are generated by 458 various awk/sed/sh scripts from a master table include/Caps; these 459 scripts actually write C initializers which are linked to the 460 compiler. Furthermore, the hash table is generated in the same way, so 461 it doesn't have to be generated at compiler startup time (another 462 benefit of this organization is that the hash table can be in 463 shareable text space). 464 465 Thus, adding a new capability is usually pretty trivial, just a matter 466 of adding one line to the include/Caps file. We will have more to say 467 about this in the section on Source-Form Translation. 468 469 Use Capability Resolution 470 471 The background problem that makes tic tricky is not the capability 472 translation itself, it is the resolution of use capabilities. Older 473 versions would not handle forward use references for this reason (that 474 is, a using terminal always had to follow its use target in the source 475 file). By doing this, they got away with a simple implementation 476 tactic; compile everything as it blows by, then resolve uses from 477 compiled entries. 478 479 This will not do for ncurses. The problem is that that the whole 480 compilation process has to be embeddable in the ncurses library so 481 that it can be called by the startup code to translate termcap entries 482 on the fly. The embedded version cannot go promiscuously writing 483 everything it translates out to disk -- for one thing, it will 484 typically be running with non-root permissions. 485 486 So our tic is designed to parse an entire terminfo file into a 487 doubly-linked circular list of entry structures in-core, and then do 488 use resolution in-memory before writing everything out. This design 489 has other advantages: it makes forward and back use-references equally 490 easy (so we get the latter for free), and it makes checking for name 491 collisions before they are written out easy to do. 492 493 And this is exactly how the embedded version works. But the 494 stand-alone user-accessible version of tic partly reverts to the 495 historical strategy; it writes to disk (not keeping in core) any entry 496 with no use references. 497 498 This is strictly a core-economy kluge, implemented because the 499 terminfo master file is large enough that some core-poor systems swap 500 like crazy when you compile it all in memory...there have been reports 501 of this process taking three hours, rather than the twenty seconds or 502 less typical on the author's development box. 503 504 So. The executable tic passes the entry-parser a hook that immediately 505 writes out the referenced entry if it has no use capabilities. The 506 compiler main loop refrains from adding the entry to the in-core list 507 when this hook fires. If some other entry later needs to reference an 508 entry that got written immediately, that is OK; the resolution code 509 will fetch it off disk when it cannot find it in core. 510 511 Name collisions will still be detected, just not as cleanly. The 512 write_entry() code complains before overwriting an entry that 513 postdates the time of tic's first call to write_entry(), Thus it will 514 complain about overwriting entries newly made during the tic run, but 515 not about overwriting ones that predate it. 516 517 Source-Form Translation 518 519 Another use of tic is to do source translation between various termcap 520 and terminfo formats. There are more variants out there than you might 521 think; the ones we know about are described in the captoinfo(1) manual 522 page. 523 524 The translation output code (dump_entry() in ncurses/dump_entry.c) is 525 shared with the infocmp(1) utility. It takes the same internal 526 representation used to generate the binary form and dumps it to 527 standard output in a specified format. 528 529 The include/Caps file has a header comment describing ways you can 530 specify source translations for nonstandard capabilities just by 531 altering the master table. It is possible to set up capability 532 aliasing or tell the compiler to plain ignore a given capability 533 without writing any C code at all. 534 535 For circumstances where you need to do algorithmic translation, there 536 are functions in parse_entry.c called after the parse of each entry 537 that are specifically intended to encapsulate such translations. This, 538 for example, is where the AIX box1 capability get translated to an 539 acsc string. 540 541Other Utilities 542 543 The infocmp utility is just a wrapper around the same entry-dumping 544 code used by tic for source translation. Perhaps the one interesting 545 aspect of the code is the use of a predicate function passed in to 546 dump_entry() to control which capabilities are dumped. This is 547 necessary in order to handle both the ordinary De-compilation case and 548 entry difference reporting. 549 550 The tput and clear utilities just do an entry load followed by a 551 tputs() of a selected capability. 552 553Style Tips for Developers 554 555 See the TO-DO file in the top-level directory of the source 556 distribution for additions that would be particularly useful. 557 558 The prefix _nc_ should be used on library public functions that are 559 not part of the curses API in order to prevent pollution of the 560 application namespace. If you have to add to or modify the function 561 prototypes in curses.h.in, read ncurses/MKlib_gen.sh first so you can 562 avoid breaking XSI conformance. Please join the ncurses mailing list. 563 See the INSTALL file in the top level of the distribution for details 564 on the list. 565 566 Look for the string FIXME in source files to tag minor bugs and 567 potential problems that could use fixing. 568 569 Do not try to auto-detect OS features in the main body of the C code. 570 That is the job of the configuration system. 571 572 To hold down complexity, do make your code data-driven. Especially, if 573 you can drive logic from a table filtered out of include/Caps, do it. 574 If you find you need to augment the data in that file in order to 575 generate the proper table, that is still preferable to ad-hoc code -- 576 that is why the fifth field (flags) is there. 577 578 Have fun! 579 580Porting Hints 581 582 The following notes are intended to be a first step towards DOS and 583 Macintosh ports of the ncurses libraries. 584 585 The following library modules are "pure curses"; they operate only on 586 the curses internal structures, do all output through other curses 587 calls (not including tputs() and putp()) and do not call any other 588 UNIX routines such as signal(2) or the stdio library. Thus, they 589 should not need to be modified for single-terminal ports. 590 591 lib_addch.c lib_addstr.c lib_bkgd.c lib_box.c lib_clear.c 592 lib_clrbot.c lib_clreol.c lib_delch.c lib_delwin.c lib_erase.c 593 lib_inchstr.c lib_insch.c lib_insdel.c lib_insstr.c lib_keyname.c 594 lib_move.c lib_mvwin.c lib_newwin.c lib_overlay.c lib_pad.c 595 lib_printw.c lib_refresh.c lib_scanw.c lib_scroll.c lib_scrreg.c 596 lib_set_term.c lib_touch.c lib_tparm.c lib_tputs.c lib_unctrl.c 597 lib_window.c panel.c 598 599 This module is pure curses, but calls outstr(): 600 601 lib_getstr.c 602 603 These modules are pure curses, except that they use tputs() and 604 putp(): 605 606 lib_beep.c lib_color.c lib_endwin.c lib_options.c lib_slk.c 607 lib_vidattr.c 608 609 This modules assist in POSIX emulation on non-POSIX systems: 610 611 sigaction.c 612 signal calls 613 614 The following source files will not be needed for a 615 single-terminal-type port. 616 617 alloc_entry.c captoinfo.c clear.c comp_captab.c comp_error.c 618 comp_hash.c comp_main.c comp_parse.c comp_scan.c dump_entry.c 619 infocmp.c parse_entry.c read_entry.c tput.c write_entry.c 620 621 The following modules will use open()/read()/write()/close()/lseek() 622 on files, but no other OS calls. 623 624 lib_screen.c 625 used to read/write screen dumps 626 627 lib_trace.c 628 used to write trace data to the logfile 629 630 Modules that would have to be modified for a port start here: 631 632 The following modules are "pure curses" but contain assumptions 633 inappropriate for a memory-mapped port. 634 635 lib_longname.c 636 assumes there may be multiple terminals 637 638 lib_acs.c 639 assumes acs_map as a double indirection 640 641 lib_mvcur.c 642 assumes cursor moves have variable cost 643 644 lib_termcap.c 645 assumes there may be multiple terminals 646 647 lib_ti.c 648 assumes there may be multiple terminals 649 650 The following modules use UNIX-specific calls: 651 652 lib_doupdate.c 653 input checking 654 655 lib_getch.c 656 read() 657 658 lib_initscr.c 659 getenv() 660 661 lib_newterm.c 662 lib_baudrate.c 663 lib_kernel.c 664 various tty-manipulation and system calls 665 666 lib_raw.c 667 various tty-manipulation calls 668 669 lib_setup.c 670 various tty-manipulation calls 671 672 lib_restart.c 673 various tty-manipulation calls 674 675 lib_tstp.c 676 signal-manipulation calls 677 678 lib_twait.c 679 gettimeofday(), select(). 680 _________________________________________________________________ 681 682 683 Eric S. Raymond <esr@snark.thyrsus.com> 684 685 (Note: This is not the bug address!) 686