X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;f=doc%2Fhtml%2Fman%2Fcurs_util.3x.html;h=6160a2cad552bffd401c3ed3752a8b6cc5fb732e;hb=610e9700ef6e0f95d03aa53242b12a8946bb62d7;hp=fcf95e1e2abcbd61e05d4237e3a5d86f3274c1f8;hpb=71c0306f0824ef2b10c4c5813fb003db48f3012e;p=ncurses.git diff --git a/doc/html/man/curs_util.3x.html b/doc/html/man/curs_util.3x.html index fcf95e1e..6160a2ca 100644 --- a/doc/html/man/curs_util.3x.html +++ b/doc/html/man/curs_util.3x.html @@ -1,7 +1,8 @@ - - +
-- -curs_util(3x) curs_util(3x) +curs_util(3x) Library calls curs_util(3x) --
- delay_output, filter, flushinp, getwin, key_name, keyname, - nofilter, putwin, unctrl, use_env, wunctrl - miscellaneous - curses utility routines +
+ delay_output, filter, flushinp, getwin, key_name, keyname, nofilter, + putwin, unctrl, use_env, use_tioctl, wunctrl - miscellaneous curses + utility routines --
+
#include <curses.h> - char *unctrl(chtype c); - wchar_t *wunctrl(cchar_t *c); - char *keyname(int c); - char *key_name(wchar_t w); + const char *unctrl(chtype ch); + wchar_t *wunctrl(cchar_t *wch); + + const char *keyname(int c); + const char *key_name(wchar_t wc); + void filter(void); - void nofilter(void); - void use_env(bool f); - int putwin(WINDOW *win, FILE *filep); - WINDOW *getwin(FILE *filep); - int delay_output(int ms); + + void use_env(bool f); + + int putwin(WINDOW *win, FILE *filep); + WINDOW *getwin(FILE *filep); + + int delay_output(int ms); int flushinp(void); + /* extensions */ + void nofilter(void); + void use_tioctl(bool f); --
- The unctrl routine returns a character string which is a - printable representation of the character c, ignoring at- - tributes. Control characters are displayed in the ^X no- - tation. Printing characters are displayed as is. The - corresponding wunctrl returns a printable representation - of a wide-character. - - The keyname routine returns a character string correspond- - ing to the key c: - - - Printable characters are displayed as themselves, - e.g., a one-character string containing the key. - - - Control characters are displayed in the ^X notation. - - - DEL (character 127) is displayed as ^?. - - - Values above 128 are either meta characters (if the - screen has not been initialized, or if meta has been - called with a TRUE parameter), shown in the M-X no- - tation, or are displayed as themselves. In the lat- - ter case, the values may not be printable; this fol- - lows the X/Open specification. - - - Values above 256 may be the names of the names of - function keys. - - - Otherwise (if there is no corresponding name) the - function returns null, to denote an error. X/Open - also lists an "UNKNOWN KEY" return value, which some - implementations return rather than null. - - The corresponding key_name returns a character string cor- - responding to the wide-character value w. The two func- - tions do not return the same set of strings; the latter - returns null where the former would display a meta charac- - ter. - - The filter routine, if used, must be called before initscr - or newterm are called. The effect is that, during those - calls, LINES is set to 1; the capabilities clear, cup, - cud, cud1, cuu1, cuu, vpa are disabled; and the home - string is set to the value of cr. - - The nofilter routine cancels the effect of a preceding - filter call. That allows the caller to initialize a - screen on a different device, using a different value of - $TERM. The limitation arises because the filter routine - modifies the in-memory copy of the terminal information. - - The use_env routine, if used, is called before initscr or - newterm are called. When called with FALSE as an argu- - ment, the values of lines and columns specified in the - terminfo database will be used, even if environment vari- - ables LINES and COLUMNS (used by default) are set, or if - curses is running in a window (in which case default be- - havior would be to use the window size if LINES and COL- - UMNS are not set). Note that setting LINES or COLUMNS - overrides the corresponding size which may be obtained - from the operating system. - - The putwin routine writes all data associated with window - win into the file to which filep points. This information - can be later retrieved using the getwin function. - - The getwin routine reads window related data stored in the - file by putwin. The routine then creates and initializes - a new window using that data. It returns a pointer to the - new window. - - The delay_output routine inserts an ms millisecond pause - in output. This routine should not be used extensively - because padding characters are used rather than a CPU - pause. If no padding character is specified, this uses - napms to perform the delay. - - The flushinp routine throws away any typeahead that has - been typed by the user and has not yet been read by the - program. +
+ +
+ The unctrl routine returns a character string which is a printable + representation of the character ch: + + o Printable characters are displayed as themselves, e.g., a one- + character string containing the key. + + o Control characters are displayed in the ^X notation. + + o Printing characters are displayed as is. + + o DEL (character 127) is displayed as ^?. + + o Values above 128 are either meta characters (if the screen has not + been initialized, or if meta(3x) has been called with a TRUE + parameter), shown in the M-X notation, or are displayed as + themselves. In the latter case, the values may not be printable; + this follows the X/Open specification. + + The corresponding wunctrl returns a printable representation of a + complex character wch. + + In both unctrl and wunctrl the attributes and color associated with the + character parameter are ignored. + + +
+ The keyname routine returns a character string corresponding to the key + c. Key codes are different from character codes. + + o Key codes below 256 are characters. They are displayed using + unctrl. + + o Values above 256 may be the codes for function keys. The function + key name is displayed. + + o Otherwise (if there is no corresponding name and the key is not a + character) the function returns null, to denote an error. X/Open + also lists an "UNKNOWN KEY" return value, which some + implementations return rather than null. + + The corresponding key_name returns a multibyte character string + corresponding to the wide-character value w. The two functions + (keyname and key_name) do not return the same set of strings: + + o keyname returns null where key_name would display a meta character. + + o key_name does not return the name of a function key. + + +
+ The filter routine, if used, must be called before initscr or newterm + are called. Calling filter causes these changes in initialization: + + o LINES is set to 1; + + o the capabilities clear, cud1, cud, cup, cuu1, cuu, vpa are + disabled; + + o the capability ed is disabled if bce is set; + + o and the home string is set to the value of cr. + + The nofilter routine cancels the effect of a preceding filter call. + That allows the caller to initialize a screen on a different device, + using a different value of $TERM. The limitation arises because the + filter routine modifies the in-memory copy of the terminal information. + + +
+ The use_env routine, if used, should be called before initscr or + newterm are called (because those compute the screen size). It + modifies the way ncurses treats environment variables when determining + the screen size. + + o Normally ncurses looks first at the terminal database for the + screen size. + + If use_env was called with FALSE for parameter, it stops here + unless use_tioctl was also called with TRUE for parameter. + + o Then it asks for the screen size via operating system calls. If + successful, it overrides the values from the terminal database. + + o Finally (unless use_env was called with FALSE parameter), ncurses + examines the LINES or COLUMNS environment variables, using a value + in those to override the results from the operating system or + terminal database. + + curses also updates the screen size in response to SIGWINCH, unless + overridden by the LINES or COLUMNS environment variables, --
- Except for flushinp, routines that return an integer re- - turn ERR upon failure and OK (SVr4 specifies only "an in- - teger value other than ERR") upon successful completion. + +
+ The use_tioctl routine, if used, should be called before initscr or + newterm are called (because those compute the screen size). After + use_tioctl is called with TRUE as an argument, ncurses modifies the + last step in its computation of screen size as follows: + + o checks if the LINES and COLUMNS environment variables are set to a + number greater than zero. + + o for each, ncurses updates the corresponding environment variable + with the value that it has obtained via operating system call or + from the terminal database. + + o ncurses re-fetches the value of the environment variables so that + it is still the environment variables which set the screen size. + + The use_env and use_tioctl routines combine as follows. + + use_env use_tioctl Summary + ----------------------------------------------------------------- + TRUE FALSE This is the default behavior. ncurses + uses operating system calls unless + overridden by LINES or COLUMNS + environment variables; default. + TRUE TRUE ncurses updates LINES and COLUMNS based + on operating system calls. + FALSE TRUE ncurses ignores LINES and COLUMNS, using + operating system calls to obtain size. + + +
+ The putwin routine writes all data associated with window (or pad) win + into the file to which filep points. This information can be later + retrieved using the getwin function. + + The getwin routine reads window related data stored in the file by + putwin. The routine then creates and initializes a new window using + that data. It returns a pointer to the new window. There are a few + caveats: + + o the data written is a copy of the WINDOW structure, and its + associated character cells. The format differs between the wide- + character (ncursesw) and non-wide (ncurses) libraries. You can + transfer data between the two, however. + + o the retrieved window is always created as a top-level window (or + pad), rather than a subwindow. + + o the window's character cells contain the color pair value, but not + the actual color numbers. If cells in the retrieved window use + color pairs which have not been created in the application using + init_pair, they will not be colored when the window is refreshed. + + +
+ The delay_output routine inserts an ms millisecond pause in output. + Employ this function judiciously when terminal output uses padding, + because ncurses transmits null characters (consuming CPU and I/O + resources) instead of sleeping and requesting resumption from the + operating system. Padding is used unless: + + o the terminal description has npc (no_pad_char) capability, or + + o the environment variable NCURSES_NO_PADDING is set. + + If padding is not in use, ncurses uses napms to perform the delay. If + the value of ms exceeds 30,000 (thirty seconds), it is capped at that + value. + + +
+ The flushinp routine throws away any typeahead that has been typed by + the user and has not yet been read by the program. + + +
+ Except for flushinp, routines that return an integer return ERR upon + failure and OK (SVr4 specifies only "an integer value other than ERR") + upon successful completion. Routines that return pointers return NULL on error. - X/Open does not define any error conditions. In this im- - plementation + X/Open Curses does not specify any error conditions. In this + implementation flushinp - returns an error if the terminal was not initial- - ized. - - meta returns an error if the terminal was not initial- - ized. + returns an error if the terminal was not initialized. putwin - returns an error if the associated fwrite calls - return an error. + returns an error if the associated fwrite calls return an + error. --
- The XSI Curses standard, Issue 4 describes these func- - tions. It states that unctrl and wunctrl will return a - null pointer if unsuccessful, but does not define any er- - ror conditions. This implementation checks for three cas- - es: - - - the parameter is a 7-bit US-ASCII code. This - is the case that X/Open Curses documented. - - - the parameter is in the range 128-159, i.e., a - C1 control code. If use_legacy_coding has - been called with a 2 parameter, unctrl returns - the parameter, i.e., a one-character string - with the parameter as the first character. - Otherwise, it returns ``~@'', ``~A'', etc., - analogous to ``^@'', ``^A'', C0 controls. - - X/Open Curses does not document whether unctrl - can be called before initializing curses. - This implementation permits that, and returns - the ``~@'', etc., values in that case. - - - parameter values outside the 0 to 255 range. - unctrl returns a null pointer. - - The SVr4 documentation describes the action of filter only - in the vaguest terms. The description here is adapted - from the XSI Curses standard (which erroneously fails to - describe the disabling of cuu). - - The strings returned by unctrl in this implementation are - determined at compile time, showing C1 controls from the - upper-128 codes with a `~' prefix rather than `^'. Other - implementations have different conventions. For example, - they may show both sets of control characters with `^', - and strip the parameter to 7 bits. Or they may ignore C1 - controls and treat all of the upper-128 codes as print- - able. This implementation uses 8 bits but does not modify - the string to reflect locale. The use_legacy_coding func- - tion allows the caller to change the output of unctrl. - - Likewise, the meta function allows the caller to change - the output of keyname, i.e., it determines whether to use - the `M-' prefix for ``meta'' keys (codes in the range 128 - to 255). Both use_legacy_coding and meta succeed only af- - ter curses is initialized. X/Open Curses does not docu- - ment the treatment of codes 128 to 159. When treating - them as ``meta'' keys (or if keyname is called before ini- - tializing curses), this implementation returns strings - ``M-^@'', ``M-^A'', etc. - - The keyname function may return the names of user-defined - string capabilities which are defined in the terminfo en- - try via the -x option of tic. This implementation auto- - matically assigns at run-time keycodes to user-defined - strings which begin with "k". The keycodes start at - KEY_MAX, but are not guaranteed to be the same value for - different runs because user-defined codes are merged from - all terminal descriptions which have been loaded. The - use_extended_names function controls whether this data is - loaded when the terminal description is read by the li- - brary. - - The nofilter routine is specific to ncurses. It was not - supported on Version 7, BSD or System V implementations. - It is recommended that any code depending on ncurses ex- - tensions be conditioned using NCURSES_VERSION. +
+
+ The SVr4 documentation describes the action of filter only in the + vaguest terms. The description here is adapted from X/Open Curses + (which erroneously fails to describe the disabling of cuu). + + +
+ The limitation to 30 seconds and the use of napms differ from other + implementations. + + o SVr4 curses does not delay if no padding character is available. --
- legacy_coding(3x), curses(3x), curs_initscr(3x), curs_ker- - nel(3x), curs_scr_dump(3x), legacy_coding(3x). + o NetBSD curses uses napms when no padding character is available, + but does not take timing into account when using the padding + character. + + Neither limits the delay. + + +
+ The keyname function may return the names of user-defined string + capabilities which are defined in the terminfo entry via the -x option + of tic. This implementation automatically assigns at run-time keycodes + to user-defined strings which begin with "k". The keycodes start at + KEY_MAX, but are not guaranteed to be the same value for different runs + because user-defined codes are merged from all terminal descriptions + which have been loaded. The use_extended_names(3x) function controls + whether this data is loaded when the terminal description is read by + the library. + + +
+ The nofilter and use_tioctl routines are specific to ncurses. They + were not supported on Version 7, BSD or System V implementations. It + is recommended that any code depending on ncurses extensions be + conditioned using NCURSES_VERSION. + + +
+ The putwin and getwin functions have several issues with portability: + + o The files written and read by these functions use an + implementation-specific format. Although the format is an obvious + target for standardization, it has been overlooked. + + Interestingly enough, according to the copyright dates in Solaris + source, the functions (along with scr_init, etc.) originated with + the University of California, Berkeley (in 1982) and were later (in + 1988) incorporated into SVr4. Oddly, there are no such functions + in the 4.3BSD curses sources. + + o Most implementations simply dump the binary WINDOW structure to the + file. These include SVr4 curses, NetBSD and PDCurses, as well as + older ncurses versions. This implementation (as well as the X/Open + variant of Solaris curses, dated 1995) uses textual dumps. + + The implementations which use binary dumps use block-I/O (the + fwrite and fread functions). Those that use textual dumps use + buffered-I/O. A few applications may happen to write extra data in + the file using these functions. Doing that can run into problems + mixing block- and buffered-I/O. This implementation reduces the + problem on writes by flushing the output. However, reading from a + file written using mixed schemes may not be successful. + + +
+ X/Open Curses, Issue 4 describes these functions. It states that + unctrl and wunctrl will return a null pointer if unsuccessful, but does + not define any error conditions. This implementation checks for three + cases: + + o the parameter is a 7-bit US-ASCII code. This is the case that + X/Open Curses documented. + + o the parameter is in the range 128-159, i.e., a C1 control code. If + use_legacy_coding(3x) has been called with a 2 parameter, unctrl + returns the parameter, i.e., a one-character string with the + parameter as the first character. Otherwise, it returns "~@", + "~A", etc., analogous to "^@", "^A", C0 controls. + + X/Open Curses does not document whether unctrl can be called before + initializing curses. This implementation permits that, and returns + the "~@", etc., values in that case. + + o parameter values outside the 0 to 255 range. unctrl returns a null + pointer. + + The strings returned by unctrl in this implementation are determined at + compile time, showing C1 controls from the upper-128 codes with a "~" + prefix rather than "^". Other implementations have different + conventions. For example, they may show both sets of control + characters with "^", and strip the parameter to 7 bits. Or they may + ignore C1 controls and treat all of the upper-128 codes as printable. + This implementation uses 8 bits but does not modify the string to + reflect locale. The use_legacy_coding(3x) function allows the caller + to change the output of unctrl. + Likewise, the meta(3x) function allows the caller to change the output + of keyname, i.e., it determines whether to use the "M-" prefix for + "meta" keys (codes in the range 128 to 255). Both + use_legacy_coding(3x) and meta(3x) succeed only after curses is + initialized. X/Open Curses does not document the treatment of codes + 128 to 159. When treating them as "meta" keys (or if keyname is called + before initializing curses), this implementation returns strings + "M-^@", "M-^A", etc. + X/Open Curses documents unctrl as declared in <unctrl.h>, which ncurses + does. However, ncurses' <curses.h> includes <unctrl.h>, matching the + behavior of SVr4 curses. Other implementations may not do that. - curs_util(3x) + +
+ If ncurses is configured to provide the sp-functions extension, the + state of use_env and use_tioctl may be updated before creating each + screen rather than once only (curs_sp_funcs(3x)). This feature of + use_env is not provided by other implementations of curses. + + +
+ curses(3x), curs_initscr(3x), curs_inopts(3x), curs_kernel(3x), + curs_scr_dump(3x), curs_sp_funcs(3x), curs_variables(3x), + legacy_coding(3x) + + + +ncurses 6.5 2024-04-20 curs_util(3x)-