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micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]32<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
33<html>
34<head>
35 <meta name="generator" content=
36 "HTML Tidy for HTML5 for Linux version 5.6.0">
37 <title>A Hacker's Guide to Ncurses Internals</title>
38 <link rel="author" href="mailto:bugs-ncurses@gnu.org">
39 <meta http-equiv="Content-Type" content=
40 "text/html; charset=us-ascii"><!--
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]41This document is self-contained, *except* that there is one relative link to
42the ncurses-intro.html document, expected to be in the same directory with
43this one.
44-->
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]45</head>
46<body>
47 <h1 class="no-header">A Hacker's Guide to NCURSES</h1>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]48
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]49 <h2>A Hacker's Guide to NCURSES</h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]50
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]51 <div class="nav">
52 <h2>Contents</h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]53
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]54 <ul>
55 <li><a href="#abstract">Abstract</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]56
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]57 <li>
58 <a href="#objective">Objective of the Package</a>
59 <ul>
60 <li><a href="#whysvr4">Why System V Curses?</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]61
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]62 <li><a href="#extensions">How to Design Extensions</a></li>
63 </ul>
64 </li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]65
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]66 <li><a href="#portability">Portability and Configuration</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]67
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]68 <li><a href="#documentation">Documentation Conventions</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]69
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]70 <li><a href="#bugtrack">How to Report Bugs</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]71
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]72 <li>
73 <a href="#ncurslib">A Tour of the Ncurses Library</a>
74 <ul>
75 <li><a href="#loverview">Library Overview</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]76
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]77 <li><a href="#engine">The Engine Room</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]78
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]79 <li><a href="#input">Keyboard Input</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]80
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]81 <li><a href="#mouse">Mouse Events</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]82
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]83 <li><a href="#output">Output and Screen Updating</a></li>
84 </ul>
85 </li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]86
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]87 <li><a href="#fmnote">The Forms and Menu Libraries</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]88
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]89 <li>
90 <a href="#tic">A Tour of the Terminfo Compiler</a>
91 <ul>
92 <li><a href="#nonuse">Translation of
93 Non-<strong>use</strong> Capabilities</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]94
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]95 <li><a href="#uses">Use Capability Resolution</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]96
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]97 <li><a href="#translation">Source-Form Translation</a></li>
98 </ul>
99 </li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]100
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]101 <li><a href="#utils">Other Utilities</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]102
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]103 <li><a href="#style">Style Tips for Developers</a></li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]104
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]105 <li><a href="#port">Porting Hints</a></li>
106 </ul>
107 </div>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]108
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]109 <h2><a name="abstract" id="abstract">Abstract</a></h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]110
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]111 <p>This document is a hacker's tour of the
112 <strong>ncurses</strong> library and utilities. It discusses
113 design philosophy, implementation methods, and the conventions
114 used for coding and documentation. It is recommended reading for
115 anyone who is interested in porting, extending or improving the
116 package.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]117
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]118 <h2><a name="objective" id="objective">Objective of the
119 Package</a></h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]120
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]121 <p>The objective of the <strong>ncurses</strong> package is to
122 provide a free software API for character-cell terminals and
123 terminal emulators with the following characteristics:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]124
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]125 <ul>
126 <li>Source-compatible with historical curses implementations
127 (including the original BSD curses and System V curses.</li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]128
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]129 <li>Conformant with the XSI Curses standard issued as part of
130 XPG4 by X/Open.</li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]131
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]132 <li>High-quality &mdash; stable and reliable code, wide
133 portability, good packaging, superior documentation.</li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]134
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]135 <li>Featureful &mdash; should eliminate as much of the drudgery
136 of C interface programming as possible, freeing programmers to
137 think at a higher level of design.</li>
138 </ul>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]139
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]140 <p>These objectives are in priority order. So, for example,
141 source compatibility with older version must trump featurefulness
142 &mdash; we cannot add features if it means breaking the portion
143 of the API corresponding to historical curses versions.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]144
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]145 <h3><a name="whysvr4" id="whysvr4">Why System V Curses?</a></h3>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]146
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]147 <p>We used System V curses as a model, reverse-engineering their
148 API, in order to fulfill the first two objectives.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]149
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]150 <p>System V curses implementations can support BSD curses
151 programs with just a recompilation, so by capturing the System V
152 API we also capture BSD's.</p>
153
154 <p>More importantly for the future, the XSI Curses standard
155 issued by X/Open is explicitly and closely modeled on System V.
156 So conformance with System V took us most of the way to
157 base-level XSI conformance.</p>
158
159 <h3><a name="extensions" id="extensions">How to Design
160 Extensions</a></h3>
161
162 <p>The third objective (standards conformance) requires that it
163 be easy to condition source code using <strong>ncurses</strong>
164 so that the absence of nonstandard extensions does not break the
165 code.</p>
166
167 <p>Accordingly, we have a policy of associating with each
168 nonstandard extension a feature macro, so that ncurses client
169 code can use this macro to condition in or out the code that
170 requires the <strong>ncurses</strong> extension.</p>
171
172 <p>For example, there is a macro
173 <code>NCURSES_MOUSE_VERSION</code> which XSI Curses does not
174 define, but which is defined in the <strong>ncurses</strong>
175 library header. You can use this to condition the calls to the
176 mouse API calls.</p>
177
178 <h2><a name="portability" id="portability">Portability and
179 Configuration</a></h2>
180
181 <p>Code written for <strong>ncurses</strong> may assume an
182 ANSI-standard C compiler and POSIX-compatible OS interface. It
183 may also assume the presence of a System-V-compatible
184 <em>select(2)</em> call.</p>
185
186 <p>We encourage (but do not require) developers to make the code
187 friendly to less-capable UNIX environments wherever possible.</p>
188
189 <p>We encourage developers to support OS-specific optimizations
190 and methods not available under POSIX/ANSI, provided only
191 that:</p>
192
193 <ul>
194 <li>All such code is properly conditioned so the build process
195 does not attempt to compile it under a plain ANSI/POSIX
196 environment.</li>
197
198 <li>Adding such implementation methods does not introduce
199 incompatibilities in the <strong>ncurses</strong> API between
200 platforms.</li>
201 </ul>
202
203 <p>We use GNU <code>autoconf(1)</code> as a tool to deal with
204 portability issues. The right way to leverage an OS-specific
205 feature is to modify the autoconf specification files
206 (configure.in and aclocal.m4) to set up a new feature macro,
207 which you then use to condition your code.</p>
208
209 <h2><a name="documentation" id="documentation">Documentation
210 Conventions</a></h2>
211
212 <p>There are three kinds of documentation associated with this
213 package. Each has a different preferred format:</p>
214
215 <ul>
216 <li>Package-internal files (README, INSTALL, TO-DO etc.)</li>
217
218 <li>Manual pages.</li>
219
220 <li>Everything else (i.e., narrative documentation).</li>
221 </ul>
222
223 <p>Our conventions are simple:</p>
224
225 <ol>
226 <li><strong>Maintain package-internal files in plain
227 text.</strong> The expected viewer for them is <em>more(1)</em> or
228 an editor window; there is no point in elaborate mark-up.</li>
229
230 <li><strong>Mark up manual pages in the man macros.</strong>
231 These have to be viewable through traditional <em>man(1)</em>
232 programs.</li>
233
234 <li><strong>Write everything else in HTML.</strong>
235 </li>
236 </ol>
237
238 <p>When in doubt, HTMLize a master and use <em>lynx(1)</em> to
239 generate plain ASCII (as we do for the announcement
240 document).</p>
241
242 <p>The reason for choosing HTML is that it is (a) well-adapted
243 for on-line browsing through viewers that are everywhere; (b)
244 more easily readable as plain text than most other mark-ups, if
245 you do not have a viewer; and (c) carries enough information that
246 you can generate a nice-looking printed version from it. Also, of
247 course, it make exporting things like the announcement document
248 to WWW pretty trivial.</p>
249
250 <h2><a name="bugtrack" id="bugtrack">How to Report Bugs</a></h2>
251
252 <p>The <a name="bugreport" id="bugreport">reporting address for
253 bugs</a> is <a href=
254 "mailto:bug-ncurses@gnu.org">bug-ncurses@gnu.org</a>. This is a
255 majordomo list; to join, write to
256 <code>bug-ncurses-request@gnu.org</code> with a message
257 containing the line:</p>
258
259 <pre class="code-block">
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]260 subscribe &lt;name&gt;@&lt;host.domain&gt;
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]261</pre>
262 <p>The <code>ncurses</code> code is maintained by a small group
263 of volunteers. While we try our best to fix bugs promptly, we
264 simply do not have a lot of hours to spend on elementary
265 hand-holding. We rely on intelligent cooperation from our users.
266 If you think you have found a bug in <code>ncurses</code>, there
267 are some steps you can take before contacting us that will help
268 get the bug fixed quickly.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]269
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]270 <p>In order to use our bug-fixing time efficiently, we put people
271 who show us they have taken these steps at the head of our queue.
272 This means that if you do not, you will probably end up at the
273 tail end and have to wait a while.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]274
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]275 <ol>
276 <li><p>Develop a recipe to reproduce the bug.
277 <p>Bugs we can reproduce are likely to be fixed very quickly,
278 often within days. The most effective single thing you can do
279 to get a quick fix is develop a way we can duplicate the bad
280 behavior &mdash; ideally, by giving us source for a small,
281 portable test program that breaks the library. (Even better
282 is a keystroke recipe using one of the test programs provided
283 with the distribution.)</p>
284 </li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]285
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]286 <li><p>Try to reproduce the bug on a different terminal type.
287 <p>In our experience, most of the behaviors people report as
288 library bugs are actually due to subtle problems in terminal
289 descriptions. This is especially likely to be true if you are
290 using a traditional asynchronous terminal or PC-based
291 terminal emulator, rather than xterm or a UNIX console
292 entry.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]293
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]294 <p>It is therefore extremely helpful if you can tell us
295 whether or not your problem reproduces on other terminal
296 types. Usually you will have both a console type and xterm
297 available; please tell us whether or not your bug reproduces
298 on both.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]299
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]300 <p>If you have xterm available, it is also good to collect
301 xterm reports for different window sizes. This is especially
302 true if you normally use an unusual xterm window size &mdash;
303 a surprising number of the bugs we have seen are either
304 triggered or masked by these.</p>
305 </li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]306
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]307 <li><p>Generate and examine a trace file for the broken behavior.
308 <p>Recompile your program with the debugging versions of the
309 libraries. Insert a <code>trace()</code> call with the
310 argument set to <code>TRACE_UPDATE</code>. (See <a href=
311 "ncurses-intro.html#debugging">"Writing Programs with
312 NCURSES"</a> for details on trace levels.) Reproduce your
313 bug, then look at the trace file to see what the library was
314 actually doing.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]315
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]316 <p>Another frequent cause of apparent bugs is application
317 coding errors that cause the wrong things to be put on the
318 virtual screen. Looking at the virtual-screen dumps in the
319 trace file will tell you immediately if this is happening,
320 and save you from the possible embarrassment of being told
321 that the bug is in your code and is your problem rather than
322 ours.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]323
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]324 <p>If the virtual-screen dumps look correct but the bug
325 persists, it is possible to crank up the trace level to give
326 more and more information about the library's update actions
327 and the control sequences it issues to perform them. The test
328 directory of the distribution contains a tool for digesting
329 these logs to make them less tedious to wade through.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]330
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]331 <p>Often you will find terminfo problems at this stage by
332 noticing that the escape sequences put out for various
333 capabilities are wrong. If not, you are likely to learn
334 enough to be able to characterize any bug in the
335 screen-update logic quite exactly.</p>
336 </li>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]337
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]338 <li><p>Report details and symptoms, not just interpretations.
339 <p>If you do the preceding two steps, it is very likely that
340 you will discover the nature of the problem yourself and be
341 able to send us a fix. This will create happy feelings all
342 around and earn you good karma for the first time you run
343 into a bug you really cannot characterize and fix
344 yourself.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]345
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]346 <p>If you are still stuck, at least you will know what to
347 tell us. Remember, we need details. If you guess about what
348 is safe to leave out, you are too likely to be wrong.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]349
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]350 <p>If your bug produces a bad update, include a trace file.
351 Try to make the trace at the <em>least</em> voluminous level
352 that pins down the bug. Logs that have been through
353 tracemunch are OK, it does not throw away any information
354 (actually they are better than un-munched ones because they
355 are easier to read).</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]356
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]357 <p>If your bug produces a core-dump, please include a
358 symbolic stack trace generated by gdb(1) or your local
359 equivalent.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]360
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]361 <p>Tell us about every terminal on which you have reproduced
362 the bug &mdash; and every terminal on which you cannot.
363 Ideally, send us terminfo sources for all of these (yours
364 might differ from ours).</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]365
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]366 <p>Include your ncurses version and your OS/machine type, of
367 course! You can find your ncurses version in the
368 <code>curses.h</code> file.</p>
369 </li>
370 </ol>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]371
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]372 <p>If your problem smells like a logic error or in cursor
373 movement or scrolling or a bad capability, there are a couple of
374 tiny test frames for the library algorithms in the progs
375 directory that may help you isolate it. These are not part of the
376 normal build, but do have their own make productions.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]377
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]378 <p>The most important of these is <code>mvcur</code>, a test
379 frame for the cursor-movement optimization code. With this
380 program, you can see directly what control sequences will be
381 emitted for any given cursor movement or scroll/insert/delete
382 operations. If you think you have got a bad capability
383 identified, you can disable it and test again. The program is
384 command-driven and has on-line help.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]385
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]386 <p>If you think the vertical-scroll optimization is broken, or
387 just want to understand how it works better, build
388 <code>hashmap</code> and read the header comments of
389 <code>hardscroll.c</code> and <code>hashmap.c</code>; then try it
390 out. You can also test the hardware-scrolling optimization
391 separately with <code>hardscroll</code>.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]392
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]393 <h2><a name="ncurslib" id="ncurslib">A Tour of the Ncurses
394 Library</a></h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]395
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]396 <h3><a name="loverview" id="loverview">Library Overview</a></h3>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]397
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]398 <p>Most of the library is superstructure &mdash; fairly trivial
399 convenience interfaces to a small set of basic functions and data
400 structures used to manipulate the virtual screen (in particular,
401 none of this code does any I/O except through calls to more
402 fundamental modules described below). The files</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]403
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]404 <blockquote>
405 <code>lib_addch.c lib_bkgd.c lib_box.c lib_chgat.c lib_clear.c
406 lib_clearok.c lib_clrbot.c lib_clreol.c lib_colorset.c
407 lib_data.c lib_delch.c lib_delwin.c lib_echo.c lib_erase.c
408 lib_gen.c lib_getstr.c lib_hline.c lib_immedok.c lib_inchstr.c
409 lib_insch.c lib_insdel.c lib_insstr.c lib_instr.c
410 lib_isendwin.c lib_keyname.c lib_leaveok.c lib_move.c
411 lib_mvwin.c lib_overlay.c lib_pad.c lib_printw.c lib_redrawln.c
412 lib_scanw.c lib_screen.c lib_scroll.c lib_scrollok.c
413 lib_scrreg.c lib_set_term.c lib_slk.c lib_slkatr_set.c
414 lib_slkatrof.c lib_slkatron.c lib_slkatrset.c lib_slkattr.c
415 lib_slkclear.c lib_slkcolor.c lib_slkinit.c lib_slklab.c
416 lib_slkrefr.c lib_slkset.c lib_slktouch.c lib_touch.c
417 lib_unctrl.c lib_vline.c lib_wattroff.c lib_wattron.c
418 lib_window.c</code>
419 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]420
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]421 <p>are all in this category. They are very unlikely to need
422 change, barring bugs or some fundamental reorganization in the
423 underlying data structures.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]424
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]425 <p>These files are used only for debugging support:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]426
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]427 <blockquote>
428 <code>lib_trace.c lib_traceatr.c lib_tracebits.c lib_tracechr.c
429 lib_tracedmp.c lib_tracemse.c trace_buf.c</code>
430 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]431
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]432 <p>It is rather unlikely you will ever need to change these,
433 unless you want to introduce a new debug trace level for some
434 reason.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]435
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]436 <p>There is another group of files that do direct I/O via
437 <em>tputs()</em>, computations on the terminal capabilities, or
438 queries to the OS environment, but nevertheless have only fairly
439 low complexity. These include:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]440
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]441 <blockquote>
442 <code>lib_acs.c lib_beep.c lib_color.c lib_endwin.c
443 lib_initscr.c lib_longname.c lib_newterm.c lib_options.c
444 lib_termcap.c lib_ti.c lib_tparm.c lib_tputs.c lib_vidattr.c
445 read_entry.c.</code>
446 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]447
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]448 <p>They are likely to need revision only if ncurses is being
449 ported to an environment without an underlying terminfo
450 capability representation.</p>
451
452 <p>These files have serious hooks into the tty driver and signal
453 facilities:</p>
454
455 <blockquote>
456 <code>lib_kernel.c lib_baudrate.c lib_raw.c lib_tstp.c
457 lib_twait.c</code>
458 </blockquote>
459
460 <p>If you run into porting snafus moving the package to another
461 UNIX, the problem is likely to be in one of these files. The file
462 <code>lib_print.c</code> uses sleep(2) and also falls in this
463 category.</p>
464
465 <p>Almost all of the real work is done in the files</p>
466
467 <blockquote>
468 <code>hardscroll.c hashmap.c lib_addch.c lib_doupdate.c
469 lib_getch.c lib_mouse.c lib_mvcur.c lib_refresh.c lib_setup.c
470 lib_vidattr.c</code>
471 </blockquote>
472
473 <p>Most of the algorithmic complexity in the library lives in
474 these files. If there is a real bug in <strong>ncurses</strong>
475 itself, it is probably here. We will tour some of these files in
476 detail below (see <a href="#engine">The Engine Room</a>).</p>
477
478 <p>Finally, there is a group of files that is actually most of
479 the terminfo compiler. The reason this code lives in the
480 <strong>ncurses</strong> library is to support fallback to
481 /etc/termcap. These files include</p>
482
483 <blockquote>
484 <code>alloc_entry.c captoinfo.c comp_captab.c comp_error.c
485 comp_hash.c comp_parse.c comp_scan.c parse_entry.c
486 read_termcap.c write_entry.c</code>
487 </blockquote>
488
489 <p>We will discuss these in the compiler tour.</p>
490
491 <h3><a name="engine" id="engine">The Engine Room</a></h3>
492
493 <h4><a name="input" id="input">Keyboard Input</a></h4>
494
495 <p>All <code>ncurses</code> input funnels through the function
496 <code>wgetch()</code>, defined in <code>lib_getch.c</code>. This
497 function is tricky; it has to poll for keyboard and mouse events
498 and do a running match of incoming input against the set of
499 defined special keys.</p>
500
501 <p>The central data structure in this module is a FIFO queue,
502 used to match multiple-character input sequences against
503 special-key capabilities; also to implement pushback via
504 <code>ungetch()</code>.</p>
505
506 <p>The <code>wgetch()</code> code distinguishes between function
507 key sequences and the same sequences typed manually by doing a
508 timed wait after each input character that could lead a function
509 key sequence. If the entire sequence takes less than 1 second, it
510 is assumed to have been generated by a function key press.</p>
511
512 <p>Hackers bruised by previous encounters with variant
513 <code>select(2)</code> calls may find the code in
514 <code>lib_twait.c</code> interesting. It deals with the problem
515 that some BSD selects do not return a reliable time-left value.
516 The function <code>timed_wait()</code> effectively simulates a
517 System V select.</p>
518
519 <h4><a name="mouse" id="mouse">Mouse Events</a></h4>
520
521 <p>If the mouse interface is active, <code>wgetch()</code> polls
522 for mouse events each call, before it goes to the keyboard for
523 input. It is up to <code>lib_mouse.c</code> how the polling is
524 accomplished; it may vary for different devices.</p>
525
526 <p>Under xterm, however, mouse event notifications come in via
527 the keyboard input stream. They are recognized by having the
528 <strong>kmous</strong> capability as a prefix. This is kind of
529 klugey, but trying to wire in recognition of a mouse key prefix
530 without going through the function-key machinery would be just
531 too painful, and this turns out to imply having the prefix
532 somewhere in the function-key capabilities at terminal-type
533 initialization.</p>
534
535 <p>This kluge only works because <strong>kmous</strong> is not
536 actually used by any historic terminal type or curses
537 implementation we know of. Best guess is it is a relic of some
538 forgotten experiment in-house at Bell Labs that did not leave any
539 traces in the publicly-distributed System V terminfo files. If
540 System V or XPG4 ever gets serious about using it again, this
541 kluge may have to change.</p>
542
543 <p>Here are some more details about mouse event handling:</p>
544
545 <p>The <code>lib_mouse()</code> code is logically split into a
546 lower level that accepts event reports in a device-dependent
547 format and an upper level that parses mouse gestures and filters
548 events. The mediating data structure is a circular queue of event
549 structures.</p>
550
551 <p>Functionally, the lower level's job is to pick up primitive
552 events and put them on the circular queue. This can happen in one
553 of two ways: either (a) <code>_nc_mouse_event()</code> detects a
554 series of incoming mouse reports and queues them, or (b) code in
555 <code>lib_getch.c</code> detects the <strong>kmous</strong>
556 prefix in the keyboard input stream and calls _nc_mouse_inline to
557 queue up a series of adjacent mouse reports.</p>
558
559 <p>In either case, <code>_nc_mouse_parse()</code> should be
560 called after the series is accepted to parse the digested mouse
561 reports (low-level events) into a gesture (a high-level or
562 composite event).</p>
563
564 <h4><a name="output" id="output">Output and Screen Updating</a></h4>
565
566 <p>With the single exception of character echoes during a
567 <code>wgetnstr()</code> call (which simulates cooked-mode line
568 editing in an ncurses window), the library normally does all its
569 output at refresh time.</p>
570
571 <p>The main job is to go from the current state of the screen (as
572 represented in the <code>curscr</code> window structure) to the
573 desired new state (as represented in the <code>newscr</code>
574 window structure), while doing as little I/O as possible.</p>
575
576 <p>The brains of this operation are the modules
577 <code>hashmap.c</code>, <code>hardscroll.c</code> and
578 <code>lib_doupdate.c</code>; the latter two use
579 <code>lib_mvcur.c</code>. Essentially, what happens looks like
580 this:</p>
581
582 <ul>
583 <li>
584 <p>The <code>hashmap.c</code> module tries to detect vertical
585 motion changes between the real and virtual screens. This
586 information is represented by the oldindex members in the
587 newscr structure. These are modified by vertical-motion and
588 clear operations, and both are re-initialized after each
589 update. To this change-journalling information, the hashmap
590 code adds deductions made using a modified Heckel algorithm
591 on hash values generated from the line contents.</p>
592 </li>
593
594 <li>
595 <p>The <code>hardscroll.c</code> module computes an optimum
596 set of scroll, insertion, and deletion operations to make the
597 indices match. It calls <code>_nc_mvcur_scrolln()</code> in
598 <code>lib_mvcur.c</code> to do those motions.</p>
599 </li>
600
601 <li>
602 <p>Then <code>lib_doupdate.c</code> goes to work. Its job is
603 to do line-by-line transformations of <code>curscr</code>
604 lines to <code>newscr</code> lines. Its main tool is the
605 routine <code>mvcur()</code> in <code>lib_mvcur.c</code>.
606 This routine does cursor-movement optimization, attempting to
607 get from given screen location A to given location B in the
608 fewest output characters possible.</p>
609 </li>
610 </ul>
611
612 <p>If you want to work on screen optimizations, you should use
613 the fact that (in the trace-enabled version of the library)
614 enabling the <code>TRACE_TIMES</code> trace level causes a report
615 to be emitted after each screen update giving the elapsed time
616 and a count of characters emitted during the update. You can use
617 this to tell when an update optimization improves efficiency.</p>
618
619 <p>In the trace-enabled version of the library, it is also
620 possible to disable and re-enable various optimizations at
621 runtime by tweaking the variable
622 <code>_nc_optimize_enable</code>. See the file
623 <code>include/curses.h.in</code> for mask values, near the
624 end.</p>
625
626 <h2><a name="fmnote" id="fmnote">The Forms and Menu Libraries</a></h2>
627
628 <p>The forms and menu libraries should work reliably in any
629 environment you can port ncurses to. The only portability issue
630 anywhere in them is what flavor of regular expressions the
631 built-in form field type TYPE_REGEXP will recognize.</p>
632
633 <p>The configuration code prefers the POSIX regex facility,
634 modeled on System V's, but will settle for BSD regexps if the
635 former is not available.</p>
636
637 <p>Historical note: the panels code was written primarily to
638 assist in porting u386mon 2.0 (comp.sources.misc v14i001-4) to
639 systems lacking panels support; u386mon 2.10 and beyond use it.
640 This version has been slightly cleaned up for
641 <code>ncurses</code>.</p>
642
643 <h2><a name="tic" id="tic">A Tour of the Terminfo Compiler</a></h2>
644
645 <p>The <strong>ncurses</strong> implementation of
646 <strong>tic</strong> is rather complex internally; it has to do a
647 trying combination of missions. This starts with the fact that,
648 in addition to its normal duty of compiling terminfo sources into
649 loadable terminfo binaries, it has to be able to handle termcap
650 syntax and compile that too into terminfo entries.</p>
651
652 <p>The implementation therefore starts with a table-driven,
653 dual-mode lexical analyzer (in <code>comp_scan.c</code>). The
654 lexer chooses its mode (termcap or terminfo) based on the first
655 &ldquo;,&rdquo; or &ldquo;:&rdquo; it finds in each entry. The
656 lexer does all the work of recognizing capability names and
657 values; the grammar above it is trivial, just "parse entries till
658 you run out of file".</p>
659
660 <h3><a name="nonuse" id="nonuse">Translation of
661 Non-<strong>use</strong> Capabilities</a></h3>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]662
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]663 <p>Translation of most things besides <strong>use</strong>
664 capabilities is pretty straightforward. The lexical analyzer's
665 tokenizer hands each capability name to a hash function, which
666 drives a table lookup. The table entry yields an index which is
667 used to look up the token type in another table, and controls
668 interpretation of the value.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]669
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]670 <p>One possibly interesting aspect of the implementation is the
671 way the compiler tables are initialized. All the tables are
672 generated by various awk/sed/sh scripts from a master table
673 <code>include/Caps</code>; these scripts actually write C
674 initializers which are linked to the compiler. Furthermore, the
675 hash table is generated in the same way, so it doesn't have to be
676 generated at compiler startup time (another benefit of this
677 organization is that the hash table can be in shareable text
678 space).</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]679
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]680 <p>Thus, adding a new capability is usually pretty trivial, just
681 a matter of adding one line to the <code>include/Caps</code>
682 file. We will have more to say about this in the section on
683 <a href="#translation">Source-Form Translation</a>.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]684
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]685 <h3><a name="uses" id="uses">Use Capability Resolution</a></h3>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]686
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]687 <p>The background problem that makes <strong>tic</strong> tricky
688 is not the capability translation itself, it is the resolution of
689 <strong>use</strong> capabilities. Older versions would not
690 handle forward <strong>use</strong> references for this reason
691 (that is, a using terminal always had to follow its use target in
692 the source file). By doing this, they got away with a simple
693 implementation tactic; compile everything as it blows by, then
694 resolve uses from compiled entries.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]695
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]696 <p>This will not do for <strong>ncurses</strong>. The problem is
697 that that the whole compilation process has to be embeddable in
698 the <strong>ncurses</strong> library so that it can be called by
699 the startup code to translate termcap entries on the fly. The
700 embedded version cannot go promiscuously writing everything it
701 translates out to disk &mdash; for one thing, it will typically
702 be running with non-root permissions.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]703
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]704 <p>So our <strong>tic</strong> is designed to parse an entire
705 terminfo file into a doubly-linked circular list of entry
706 structures in-core, and then do <strong>use</strong> resolution
707 in-memory before writing everything out. This design has other
708 advantages: it makes forward and back use-references equally easy
709 (so we get the latter for free), and it makes checking for name
710 collisions before they are written out easy to do.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]711
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]712 <p>And this is exactly how the embedded version works. But the
713 stand-alone user-accessible version of <strong>tic</strong>
714 partly reverts to the historical strategy; it writes to disk (not
715 keeping in core) any entry with no <strong>use</strong>
716 references.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]717
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]718 <p>This is strictly a core-economy kluge, implemented because the
719 terminfo master file is large enough that some core-poor systems
720 swap like crazy when you compile it all in memory...there have
721 been reports of this process taking <strong>three hours</strong>,
722 rather than the twenty seconds or less typical on the author's
723 development box.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]724
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]725 <p>So. The executable <strong>tic</strong> passes the
726 entry-parser a hook that <em>immediately</em> writes out the
727 referenced entry if it has no use capabilities. The compiler main
728 loop refrains from adding the entry to the in-core list when this
729 hook fires. If some other entry later needs to reference an entry
730 that got written immediately, that is OK; the resolution code
731 will fetch it off disk when it cannot find it in core.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]732
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]733 <p>Name collisions will still be detected, just not as cleanly.
734 The <code>write_entry()</code> code complains before overwriting
735 an entry that postdates the time of <strong>tic</strong>'s first
736 call to <code>write_entry()</code>, Thus it will complain about
737 overwriting entries newly made during the <strong>tic</strong>
738 run, but not about overwriting ones that predate it.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]739
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]740 <h3><a name="translation" id="translation">Source-Form
741 Translation</a></h3>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]742
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]743 <p>Another use of <strong>tic</strong> is to do source
744 translation between various termcap and terminfo formats. There
745 are more variants out there than you might think; the ones we
746 know about are described in the <strong>captoinfo(1)</strong>
747 manual page.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]748
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]749 <p>The translation output code (<code>dump_entry()</code> in
750 <code>ncurses/dump_entry.c</code>) is shared with the
751 <strong>infocmp(1)</strong> utility. It takes the same internal
752 representation used to generate the binary form and dumps it to
753 standard output in a specified format.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]754
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]755 <p>The <code>include/Caps</code> file has a header comment
756 describing ways you can specify source translations for
757 nonstandard capabilities just by altering the master table. It is
758 possible to set up capability aliasing or tell the compiler to
759 plain ignore a given capability without writing any C code at
760 all.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]761
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]762 <p>For circumstances where you need to do algorithmic
763 translation, there are functions in <code>parse_entry.c</code>
764 called after the parse of each entry that are specifically
765 intended to encapsulate such translations. This, for example, is
766 where the AIX <strong>box1</strong> capability get translated to
767 an <strong>acsc</strong> string.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]768
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]769 <h2><a name="utils" id="utils">Other Utilities</a></h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]770
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]771 <p>The <strong>infocmp</strong> utility is just a wrapper around
772 the same entry-dumping code used by <strong>tic</strong> for
773 source translation. Perhaps the one interesting aspect of the
774 code is the use of a predicate function passed in to
775 <code>dump_entry()</code> to control which capabilities are
776 dumped. This is necessary in order to handle both the ordinary
777 De-compilation case and entry difference reporting.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]778
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]779 <p>The <strong>tput</strong> and <strong>clear</strong> utilities
780 just do an entry load followed by a <code>tputs()</code> of a
781 selected capability.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]782
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]783 <h2><a name="style" id="style">Style Tips for Developers</a></h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]784
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]785 <p>See the TO-DO file in the top-level directory of the source
786 distribution for additions that would be particularly useful.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]787
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]788 <p>The prefix <code>_nc_</code> should be used on library public
789 functions that are not part of the curses API in order to prevent
790 pollution of the application namespace. If you have to add to or
791 modify the function prototypes in curses.h.in, read
792 ncurses/MKlib_gen.sh first so you can avoid breaking XSI
793 conformance. Please join the ncurses mailing list. See the
794 INSTALL file in the top level of the distribution for details on
795 the list.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]796
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]797 <p>Look for the string <code>FIXME</code> in source files to tag
798 minor bugs and potential problems that could use fixing.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]799
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]800 <p>Do not try to auto-detect OS features in the main body of the
801 C code. That is the job of the configuration system.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]802
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]803 <p>To hold down complexity, do make your code data-driven.
804 Especially, if you can drive logic from a table filtered out of
805 <code>include/Caps</code>, do it. If you find you need to augment
806 the data in that file in order to generate the proper table, that
807 is still preferable to ad-hoc code &mdash; that is why the fifth
808 field (flags) is there.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]809
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]810 <p>Have fun!</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]811
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]812 <h2><a name="port" id="port">Porting Hints</a></h2>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]813
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]814 <p>The following notes are intended to be a first step towards
815 DOS and Macintosh ports of the ncurses libraries.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]816
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]817 <p>The following library modules are &ldquo;pure curses&rdquo;;
818 they operate only on the curses internal structures, do all
819 output through other curses calls (not including
820 <code>tputs()</code> and <code>putp()</code>) and do not call any
821 other UNIX routines such as signal(2) or the stdio library. Thus,
822 they should not need to be modified for single-terminal
823 ports.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]824
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]825 <blockquote>
826 <code>lib_addch.c lib_addstr.c lib_bkgd.c lib_box.c lib_clear.c
827 lib_clrbot.c lib_clreol.c lib_delch.c lib_delwin.c lib_erase.c
828 lib_inchstr.c lib_insch.c lib_insdel.c lib_insstr.c
829 lib_keyname.c lib_move.c lib_mvwin.c lib_newwin.c lib_overlay.c
830 lib_pad.c lib_printw.c lib_refresh.c lib_scanw.c lib_scroll.c
831 lib_scrreg.c lib_set_term.c lib_touch.c lib_tparm.c lib_tputs.c
832 lib_unctrl.c lib_window.c panel.c</code>
833 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]834
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]835 <p>This module is pure curses, but calls outstr():</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]836
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]837 <blockquote>
838 <code>lib_getstr.c</code>
839 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]840
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]841 <p>These modules are pure curses, except that they use
842 <code>tputs()</code> and <code>putp()</code>:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]843
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]844 <blockquote>
845 <code>lib_beep.c lib_color.c lib_endwin.c lib_options.c
846 lib_slk.c lib_vidattr.c</code>
847 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]848
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]849 <p>This modules assist in POSIX emulation on non-POSIX
850 systems:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]851
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]852 <dl>
853 <dt>sigaction.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]854
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]855 <dd>signal calls</dd>
856 </dl>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]857
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]858 <p>The following source files will not be needed for a
859 single-terminal-type port.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]860
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]861 <blockquote>
862 <code>alloc_entry.c captoinfo.c clear.c comp_captab.c
863 comp_error.c comp_hash.c comp_main.c comp_parse.c comp_scan.c
864 dump_entry.c infocmp.c parse_entry.c read_entry.c tput.c
865 write_entry.c</code>
866 </blockquote>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]867
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]868 <p>The following modules will use
869 open()/read()/write()/close()/lseek() on files, but no other OS
870 calls.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]871
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]872 <dl>
873 <dt>lib_screen.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]874
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]875 <dd>used to read/write screen dumps</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]876
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]877 <dt>lib_trace.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]878
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]879 <dd>used to write trace data to the logfile</dd>
880 </dl>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]881
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]882 <p>Modules that would have to be modified for a port start
883 here:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]884
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]885 <p>The following modules are &ldquo;pure curses&rdquo; but
886 contain assumptions inappropriate for a memory-mapped port.</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]887
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]888 <dl>
889 <dt>lib_longname.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]890
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]891 <dd>assumes there may be multiple terminals</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]892
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]893 <dt>lib_acs.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]894
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]895 <dd>assumes acs_map as a double indirection</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]896
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]897 <dt>lib_mvcur.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]898
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]899 <dd>assumes cursor moves have variable cost</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]900
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]901 <dt>lib_termcap.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]902
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]903 <dd>assumes there may be multiple terminals</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]904
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]905 <dt>lib_ti.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]906
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]907 <dd>assumes there may be multiple terminals</dd>
908 </dl>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]909
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]910 <p>The following modules use UNIX-specific calls:</p>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]911
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]912 <dl>
913 <dt>lib_doupdate.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]914
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]915 <dd>input checking</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]916
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]917 <dt>lib_getch.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]918
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]919 <dd>read()</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]920
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]921 <dt>lib_initscr.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]922
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]923 <dd>getenv()</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]924
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]925 <dt>lib_newterm.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]926
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]927 <dt>lib_baudrate.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]928
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]929 <dt>lib_kernel.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]930
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]931 <dd>various tty-manipulation and system calls</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]932
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]933 <dt>lib_raw.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]934
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]935 <dd>various tty-manipulation calls</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]936
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]937 <dt>lib_setup.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]938
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]939 <dd>various tty-manipulation calls</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]940
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]941 <dt>lib_restart.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]942
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]943 <dd>various tty-manipulation calls</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]944
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]945 <dt>lib_tstp.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]946
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]947 <dd>signal-manipulation calls</dd>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]948
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]949 <dt>lib_twait.c</dt>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]950
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]951 <dd>gettimeofday(), select().</dd>
952 </dl>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]953
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]954 <hr>
Amit Daniel Kachhape6a01f52011-07-20 11:45:59 +0530[diff] [blame]955
micky3879b9f5e72025-07-08 18:04:53 -0400[diff] [blame]956 <address>
957 Eric S. Raymond &lt;esr@snark.thyrsus.com&gt;
958 </address>
959 (Note: This is <em>not</em> the <a href="#bugtrack">bug
960 address</a>!)
961</body>
962</html>