1curs_terminfo(3X) curs_terminfo(3X)
2
6 del_curterm, mvcur, putp, restartterm, set_curterm, setterm, setupterm,
7 tigetflag, tigetnum, tigetstr, tiparm, tparm, tputs, vid_attr,
8 vid_puts, vidattr, vidputs - curses interfaces to terminfo database
9
11 #include <curses.h>
12 #include <term.h>
13 TERMINAL *cur_term;
15 const char * const boolnames[];
17 const char * const boolcodes[];
18 const char * const boolfnames[];
19 const char * const numnames[];
20 const char * const numcodes[];
21 const char * const numfnames[];
22 const char * const strnames[];
23 const char * const strcodes[];
24 const char * const strfnames[];
25 int setupterm(const char *term, int filedes, int *errret);
27 int setterm(const char *term);
28 TERMINAL *set_curterm(TERMINAL *nterm);
29 int del_curterm(TERMINAL *oterm);
30 int restartterm(const char *term, int filedes, int *errret);
31 char *tparm(const char *str, ...);
33 int tputs(const char *str, int affcnt, int (*putc)(int));
34 int putp(const char *str);
35 int vidputs(chtype attrs, int (*putc)(int));
37 int vidattr(chtype attrs);
38 int vid_puts(attr_t attrs, short pair, void *opts, int (*putc)(int));
39 int vid_attr(attr_t attrs, short pair, void *opts);
40 int mvcur(int oldrow, int oldcol, int newrow, int newcol);
42 int tigetflag(const char *capname);
44 int tigetnum(const char *capname);
45 char *tigetstr(const char *capname);
46 char *tiparm(const char *str, ...);
48
50 These low-level routines must be called by programs that have to deal
51 directly with the terminfo database to handle certain terminal capabil‐
52 ities, such as programming function keys. For all other functionality,
53 curses routines are more suitable and their use is recommended.
54 Initialization
56 Initially, setupterm should be called. The high-level curses functions
57 initscr and newterm call setupterm to initialize the low-level set of
58 terminal-dependent variables [listed in terminfo(5)].
59 Applications can use the terminal capabilities either directly (via
61 header definitions), or by special functions. The header files curs‐
62 es.h and term.h should be included (in this order) to get the defini‐
63 tions for these strings, numbers, and flags.
64 The terminfo variables lines and columns are initialized by setupterm
66 as follows:
67 · If use_env(FALSE) has been called, values for lines and columns
69 specified in terminfo are used.
70 · Otherwise, if the environment variables LINES and COLUMNS exist,
72 their values are used. If these environment variables do not exist
73 and the program is running in a window, the current window size is
74 used. Otherwise, if the environment variables do not exist, the
75 values for lines and columns specified in the terminfo database are
76 used.
77 Parameterized strings should be passed through tparm to instantiate
79 them. All terminfo strings (including the output of tparm) should be
80 printed with tputs or putp. Call reset_shell_mode to restore the tty
81 modes before exiting [see curs_kernel(3X)].
82 Programs which use cursor addressing should
84 · output enter_ca_mode upon startup and
86 · output exit_ca_mode before exiting.
88 Programs which execute shell subprocesses should
90 · call reset_shell_mode and output exit_ca_mode before the shell is
92 called and
93 · output enter_ca_mode and call reset_prog_mode after returning from
95 the shell.
96 The setupterm routine reads in the terminfo database, initializing the
98 terminfo structures, but does not set up the output virtualization
99 structures used by curses. These are its parameters:
100 term is the terminal type, a character string. If term is null, the
102 environment variable TERM is used.
103 filedes
105 is the file descriptor used for all output.
106 errret
108 points to an optional location where an error status can be re‐
109 turned to the caller. If errret is not null, then setupterm
110 returns OK or ERR and stores a status value in the integer
111 pointed to by errret. A return value of OK combined with sta‐
112 tus of 1 in errret is normal.
113 If ERR is returned, examine errret:
115 1 means that the terminal is hardcopy, cannot be used for
117 curses applications.
118 setupterm determines if the entry is a hardcopy type by
120 checking the hc (hardcopy) capability.
121 0 means that the terminal could not be found, or that it is
123 a generic type, having too little information for curses
124 applications to run.
125 setupterm determines if the entry is a generic type by
127 checking the gn (generic) capability.
128 -1 means that the terminfo database could not be found.
130 If errret is null, setupterm prints an error message upon find‐
132 ing an error and exits. Thus, the simplest call is:
133 setupterm((char *)0, 1, (int *)0);,
135 which uses all the defaults and sends the output to stdout.
137 The setterm routine was replaced by setupterm. The call:
139 setupterm(term, 1, (int *)0)
141 provides the same functionality as setterm(term). The setterm routine
143 is provided for BSD compatibility, and is not recommended for new pro‐
144 grams.
145 The Terminal State
147 The setupterm routine stores its information about the terminal in a
148 TERMINAL structure pointed to by the global variable cur_term. If it
149 detects an error, or decides that the terminal is unsuitable (hardcopy
150 or generic), it discards this information, making it not available to
151 applications.
152 If setupterm is called repeatedly for the same terminal type, it will
154 reuse the information. It maintains only one copy of a given termi‐
155 nal's capabilities in memory. If it is called for different terminal
156 types, setupterm allocates new storage for each set of terminal capa‐
157 bilities.
158 The set_curterm routine sets cur_term to nterm, and makes all of the
160 terminfo boolean, numeric, and string variables use the values from
161 nterm. It returns the old value of cur_term.
162 The del_curterm routine frees the space pointed to by oterm and makes
164 it available for further use. If oterm is the same as cur_term, refer‐
165 ences to any of the terminfo boolean, numeric, and string variables
166 thereafter may refer to invalid memory locations until another se‐
167 tupterm has been called.
168 The restartterm routine is similar to setupterm and initscr, except
170 that it is called after restoring memory to a previous state (for exam‐
171 ple, when reloading a game saved as a core image dump). restartterm
172 assumes that the windows and the input and output options are the same
173 as when memory was saved, but the terminal type and baud rate may be
174 different. Accordingly, restartterm saves various tty state bits,
175 calls setupterm, and then restores the bits.
176 Formatting Output
178 The tparm routine instantiates the string str with parameters pi. A
179 pointer is returned to the result of str with the parameters applied.
180 Application developers should keep in mind these quirks of the inter‐
181 face:
182 · Although tparm's actual parameters may be integers or strings, the
184 prototype expects long (integer) values.
185 · Aside from the set_attributes (sgr) capability, most terminal capa‐
187 bilities require no more than one or two parameters.
188 tiparm is a newer form of tparm which uses <stdarg.h> rather than a
190 fixed-parameter list. Its numeric parameters are integers (int) rather
191 than longs.
192 Output Functions
194 The tputs routine applies padding information to the string str and
195 outputs it:
196 · The str parameter must be a terminfo string variable or the return
198 value from tparm, tiparm, tgetstr, or tgoto.
199 The tgetstr and tgoto functions are part of the termcap interface,
201 which happens to share this function name with the terminfo inter‐
202 face.
203 · affcnt is the number of lines affected, or 1 if not applicable.
205 · putc is a putchar-like routine to which the characters are passed,
207 one at a time.
208 The putp routine calls tputs(str, 1, putchar). The output of putp al‐
210 ways goes to stdout, rather than the filedes specified in setupterm.
211 The vidputs routine displays the string on the terminal in the video
213 attribute mode attrs, which is any combination of the attributes listed
214 in curses(3X). The characters are passed to the putchar-like routine
215 putc.
216 The vidattr routine is like the vidputs routine, except that it outputs
218 through putchar.
219 The vid_attr and vid_puts routines correspond to vidattr and vidputs,
221 respectively. They use a set of arguments for representing the video
222 attributes plus color, i.e.,
223 · attrs of type attr_t for the attributes and
225 · pair of type short for the color-pair number.
227 The vid_attr and vid_puts routines are designed to use the attribute
229 constants with the WA_ prefix.
230 X/Open Curses reserves the opts argument for future use, saying that
232 applications must provide a null pointer for that argument. As an ex‐
233 tension, this implementation allows opts to be used as a pointer to
234 int, which overrides the pair (short) argument.
235 The mvcur routine provides low-level cursor motion. It takes effect
237 immediately (rather than at the next refresh).
238 Terminal Capability Functions
240 The tigetflag, tigetnum and tigetstr routines return the value of the
241 capability corresponding to the terminfo capname passed to them, such
242 as xenl. The capname for each capability is given in the table column
243 entitled capname code in the capabilities section of terminfo(5).
244 These routines return special values to denote errors.
246 The tigetflag routine returns
248 -1 if capname is not a boolean capability, or
250 0 if it is canceled or absent from the terminal description.
252 The tigetnum routine returns
254 -2 if capname is not a numeric capability, or
256 -1 if it is canceled or absent from the terminal description.
258 The tigetstr routine returns
260 (char *)-1
262 if capname is not a string capability, or
263 0 if it is canceled or absent from the terminal description.
265 Terminal Capability Names
267 These null-terminated arrays contain
268 · the short terminfo names (“codes”),
270 · the termcap names (“names”, and
272 · the long terminfo names (“fnames”)
274 for each of the predefined terminfo variables:
276 const char *boolnames[], *boolcodes[], *boolfnames[]
278 const char *numnames[], *numcodes[], *numfnames[]
279 const char *strnames[], *strcodes[], *strfnames[]
280
282 Routines that return an integer return ERR upon failure and OK (SVr4
283 only specifies “an integer value other than ERR”) upon successful com‐
284 pletion, unless otherwise noted in the preceding routine descriptions.
285 Routines that return pointers always return NULL on error.
287 X/Open defines no error conditions. In this implementation
289 del_curterm
291 returns an error if its terminal parameter is null.
292 putp calls tputs, returning the same error-codes.
294 restartterm
296 returns an error if the associated call to setupterm returns an
297 error.
298 setupterm
300 returns an error if it cannot allocate enough memory, or create
301 the initial windows (stdscr, curscr, newscr). Other error con‐
302 ditions are documented above.
303 tputs
305 returns an error if the string parameter is null. It does not
306 detect I/O errors: X/Open states that tputs ignores the return
307 value of the output function putc.
308
310 SVr2 introduced the terminfo feature. Its programming manual mentioned
311 these low-level functions:
312 Function Description
314 ────────────────────────────────────────────────────────────
315 fixterm restore tty to “in curses” state
316 gettmode establish current tty modes
317 mvcur low level cursor motion
318 putp utility function that uses tputs to send char‐
319 acters via putchar.
320 resetterm set tty modes to “out of curses” state
321 resetty reset tty flags to stored value
322 saveterm save current modes as “in curses” state
323 savetty store current tty flags
324 setterm establish terminal with given type
325 setupterm establish terminal with given type
326 tparm instantiate a string expression with parameters
327 tputs apply padding information to a string
328 vidattr like vidputs, but outputs through putchar
329 vidputs output a string to put terminal in a specified
330 video attribute mode
331 The programming manual also mentioned functions provided for termcap
333 compatibility (commenting that they “may go away at a later date”):
334 Function Description
336 ────────────────────────────────────────────────
337 tgetent look up termcap entry for given name
338 tgetflag get boolean entry for given id
339 tgetnum get numeric entry for given id
340 tgetstr get string entry for given id
341 tgoto apply parameters to given capability
342 tputs apply padding to capability, calling
343 a function to put characters
344 Early terminfo programs obtained capability values from the TERMINAL
346 structure initialized by setupterm.
347 SVr3 extended terminfo by adding functions to retrieve capability val‐
349 ues (like the termcap interface), and reusing tgoto and tputs:
350 Function Description
352 ───────────────────────────────────────────
353 tigetflag get boolean entry for given id
354 tigetnum get numeric entry for given id
355 tigetstr get string entry for given id
356 SVr3 also replaced several of the SVr2 terminfo functions which had no
358 counterpart in the termcap interface, documenting them as obsolete:
359 Function Replaced by
361 ─────────────────────────────
362 crmode cbreak
363 fixterm reset_prog_mode
364 gettmode N/A
365 nocrmode nocbreak
366 resetterm reset_shell_mode
367 saveterm def_prog_mode
368 setterm setupterm
369 SVr3 kept the mvcur, vidattr and vidputs functions, along with putp,
371 tparm and tputs. The latter were needed to support padding, and han‐
372 dling functions such as vidattr (which used more than the two parame‐
373 ters supported by tgoto).
374 SVr3 introduced the functions for switching between terminal descrip‐
376 tions, e.g., set_curterm. The various global variables such as bool‐
377 names were mentioned in the programming manual at this point.
378 SVr4 added the vid_attr and vid_puts functions.
380 There are other low-level functions declared in the curses header files
382 on Unix systems, but none were documented. The functions marked “obso‐
383 lete” remained in use by the Unix vi editor.
384
386 Legacy functions
387 X/Open notes that vidattr and vidputs may be macros.
388 The function setterm is not described by X/Open and must be considered
390 non-portable. All other functions are as described by X/Open.
391 Legacy data
393 setupterm copies the terminal name to the array ttytype. This is not
394 part of X/Open Curses, but is assumed by some applications.
395 Other implementions may not declare the capability name arrays. Some
397 provide them without declaring them. X/Open does not specify them.
398 Extended terminal capability names, e.g., as defined by tic -x, are not
400 stored in the arrays described here.
401 Output buffering
403 Older versions of ncurses assumed that the file descriptor passed to
404 setupterm from initscr or newterm uses buffered I/O, and would write to
405 the corresponding stream. In addition to the limitation that the ter‐
406 minal was left in block-buffered mode on exit (like System V curses),
407 it was problematic because ncurses did not allow a reliable way to
408 cleanup on receiving SIGTSTP.
409 The current version (ncurses6) uses output buffers managed directly by
411 ncurses. Some of the low-level functions described in this manual page
412 write to the standard output. They are not signal-safe. The high-lev‐
413 el functions in ncurses use alternate versions of these functions using
414 the more reliable buffering scheme.
415 Function prototypes
417 The X/Open Curses prototypes are based on the SVr4 curses header decla‐
418 rations, which were defined at the same time the C language was first
419 standardized in the late 1980s.
420 · X/Open Curses uses const less effectively than a later design
422 might, in some cases applying it needlessly to values are already
423 constant, and in most cases overlooking parameters which normally
424 would use const. Using constant parameters for functions which do
425 not use const may prevent the program from compiling. On the other
426 hand, writable strings are an obsolescent feature.
427 As an extension, this implementation can be configured to change
429 the function prototypes to use the const keyword. The ncurses ABI
430 6 enables this feature by default.
431 · X/Open Curses prototypes tparm with a fixed number of parameters,
433 rather than a variable argument list.
434 This implementation uses a variable argument list, but can be con‐
436 figured to use the fixed-parameter list. Portable applications
437 should provide 9 parameters after the format; zeroes are fine for
438 this purpose.
439 In response to review comments by Thomas E. Dickey, X/Open Curses
441 Issue 7 proposed the tiparm function in mid-2009.
442 Special TERM treatment
444 If configured to use the terminal-driver, e.g., for the MinGW port,
445 · setupterm interprets a missing/empty TERM variable as the special
447 value “unknown”.
448 · setupterm allows explicit use of the the windows console driver by
450 checking if $TERM is set to “#win32con” or an abbreviation of that
451 string.
452 Other portability issues
454 In System V Release 4, set_curterm has an int return type and returns
455 OK or ERR. We have chosen to implement the X/Open Curses semantics.
456 In System V Release 4, the third argument of tputs has the type int
458 (*putc)(char).
459 At least one implementation of X/Open Curses (Solaris) returns a value
461 other than OK/ERR from tputs. That returns the length of the string,
462 and does no error-checking.
463 X/Open notes that after calling mvcur, the curses state may not match
465 the actual terminal state, and that an application should touch and re‐
466 fresh the window before resuming normal curses calls. Both ncurses and
467 System V Release 4 curses implement mvcur using the SCREEN data allo‐
468 cated in either initscr or newterm. So though it is documented as a
469 terminfo function, mvcur is really a curses function which is not well
470 specified.
471 X/Open states that the old location must be given for mvcur. This im‐
473 plementation allows the caller to use -1's for the old ordinates. In
474 that case, the old location is unknown.
475
477 curses(3X), curs_initscr(3X), curs_kernel(3X), curs_termcap(3X),
478 curs_variables(3X), term_variables(3X), putc(3), terminfo(5)
479 curs_terminfo(3X)