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diff --git a/upstream/archlinux/man3/curs_terminfo.3x b/upstream/archlinux/man3/curs_terminfo.3x new file mode 100644 index 00000000..737104db --- /dev/null +++ b/upstream/archlinux/man3/curs_terminfo.3x @@ -0,0 +1,776 @@ +.\"*************************************************************************** +.\" Copyright 2018-2022,2023 Thomas E. Dickey * +.\" Copyright 1998-2016,2017 Free Software Foundation, Inc. * +.\" * +.\" Permission is hereby granted, free of charge, to any person obtaining a * +.\" copy of this software and associated documentation files (the * +.\" "Software"), to deal in the Software without restriction, including * +.\" without limitation the rights to use, copy, modify, merge, publish, * +.\" distribute, distribute with modifications, sublicense, and/or sell * +.\" copies of the Software, and to permit persons to whom the Software is * +.\" furnished to do so, subject to the following conditions: * +.\" * +.\" The above copyright notice and this permission notice shall be included * +.\" in all copies or substantial portions of the Software. * +.\" * +.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * +.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * +.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * +.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * +.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * +.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * +.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE. * +.\" * +.\" Except as contained in this notice, the name(s) of the above copyright * +.\" holders shall not be used in advertising or otherwise to promote the * +.\" sale, use or other dealings in this Software without prior written * +.\" authorization. * +.\"*************************************************************************** +.\" +.\" $Id: curs_terminfo.3x,v 1.85 2023/04/23 20:52:38 tom Exp $ +.TH curs_terminfo 3X "" +.ie \n(.g .ds `` \(lq +.el .ds `` `` +.ie \n(.g .ds '' \(rq +.el .ds '' '' +.de bP +.ie n .IP \(bu 4 +.el .IP \(bu 2 +.. +.ds n 5 +.na +.hy 0 +.SH NAME +\fBdel_curterm\fP, +\fBmvcur\fP, +\fBputp\fP, +\fBrestartterm\fP, +\fBset_curterm\fP, +\fBsetupterm\fP, +\fBtigetflag\fP, +\fBtigetnum\fP, +\fBtigetstr\fP, +\fBtiparm\fP, +\fBtiparm_s\fP, +\fBtiscan_s\fP, +\fBtparm\fP, +\fBtputs\fP, +\fBvid_attr\fP, +\fBvid_puts\fP, +\fBvidattr\fP, +\fBvidputs\fP \- \fBcurses\fP interfaces to terminfo database +.ad +.hy +.SH SYNOPSIS +.nf +\fB#include <curses.h>\fP +\fB#include <term.h>\fP +.sp +\fBTERMINAL *cur_term;\fP +.sp +\fBconst char * const boolnames[];\fP +\fBconst char * const boolcodes[];\fP +\fBconst char * const boolfnames[];\fP +\fBconst char * const numnames[];\fP +\fBconst char * const numcodes[];\fP +\fBconst char * const numfnames[];\fP +\fBconst char * const strnames[];\fP +\fBconst char * const strcodes[];\fP +\fBconst char * const strfnames[];\fP +.sp +\fBint setupterm(const char *\fIterm\fB, int \fIfiledes\fB, int *\fIerrret\fB);\fR +.br +\fBTERMINAL *set_curterm(TERMINAL *\fInterm\fB);\fR +.br +\fBint del_curterm(TERMINAL *\fIoterm\fB);\fR +.br +\fBint restartterm(const char *\fIterm\fB, int \fIfiledes\fB, int *\fIerrret\fB);\fR +.sp +\fBchar *tparm(const char *\fIstr\fB, ...);\fR +.br + \fIor\fP +.br +\fBchar *tparm(const char *\fIstr\fB, long \fIp1 ... \fBlong \fIp9\fB);\fR +.sp +\fBint tputs(const char *\fIstr\fB, int \fIaffcnt\fB, int (*\fIputc\fB)(int));\fR +.br +\fBint putp(const char *\fIstr\fB);\fR +.sp +\fBint vidputs(chtype \fIattrs\fB, int (*\fIputc\fB)(int));\fR +.br +\fBint vidattr(chtype \fIattrs\fB);\fR +.br +\fBint vid_puts(attr_t \fIattrs\fB, short \fIpair\fB, void *\fIopts\fB, int (*\fIputc\fB)(int));\fR +.br +\fBint vid_attr(attr_t \fIattrs\fB, short \fIpair\fB, void *\fIopts\fB);\fR +.sp +\fBint mvcur(int \fIoldrow\fB, int \fIoldcol\fB, int \fInewrow\fR, int \fInewcol\fB);\fR +.sp +\fBint tigetflag(const char *\fIcapname\fB);\fR +.br +\fBint tigetnum(const char *\fIcapname\fB);\fR +.br +\fBchar *tigetstr(const char *\fIcapname\fB);\fR +.sp +\fBchar *tiparm(const char *\fIstr\fB, ...);\fR +.sp +/* extensions */ +.br +\fBchar *tiparm_s(int \fIexpected\fB, int \fImask\fB, const char *\fIstr\fB, ...);\fR +.br +\fBint tiscan_s(int *\fIexpected\fB, int *\fImask\fB, const char *\fIstr\fB);\fR +.br +.fi +.SH DESCRIPTION +These low-level routines must be called by programs that have to deal +directly with the \fBterminfo\fP database to handle certain terminal +capabilities, such as programming function keys. +For all other +functionality, \fBcurses\fP routines are more suitable and their use is +recommended. +.PP +None of these functions use (or are aware of) multibyte character strings +such as UTF-8: +.bP +capability names use the POSIX portable character set +.bP +capability string values have no associated encoding; +they are strings of 8-bit characters. +.SS Initialization +.PP +Initially, \fBsetupterm\fP should be called. +The high-level curses functions \fBinitscr\fP and +\fBnewterm\fP call \fBsetupterm\fP to initialize the +low-level set of terminal-dependent variables +[listed in \fBterminfo\fP(\*n)]. +.PP +Applications can use the +terminal capabilities either directly (via header definitions), +or by special functions. +The header files \fBcurses.h\fP and \fBterm.h\fP should be included (in this +order) to get the definitions for these strings, numbers, and flags. +.PP +The \fBterminfo\fP variables +\fBlines\fP and \fBcolumns\fP are initialized by \fBsetupterm\fP as +follows: +.bP +If \fBuse_env(FALSE)\fP has been called, values for +\fBlines\fP and \fBcolumns\fP specified in \fBterminfo\fP are used. +.bP +Otherwise, if the environment variables \fBLINES\fP and \fBCOLUMNS\fP +exist, their values are used. +If these environment variables do not +exist and the program is running in a window, the current window size +is used. +Otherwise, if the environment variables do not exist, the +values for \fBlines\fP and \fBcolumns\fP specified in the +\fBterminfo\fP database are used. +.PP +Parameterized strings should be passed through \fBtparm\fP to instantiate them. +All \fBterminfo\fP strings +(including the output of \fBtparm\fP) +should be printed +with \fBtputs\fP or \fBputp\fP. +Call \fBreset_shell_mode\fP to restore the +tty modes before exiting [see \fBcurs_kernel\fP(3X)]. +.PP +Programs which use +cursor addressing should +.bP +output \fBenter_ca_mode\fP upon startup and +.bP +output \fBexit_ca_mode\fP before exiting. +.PP +Programs which execute shell subprocesses should +.bP +call \fBreset_shell_mode\fP and +output \fBexit_ca_mode\fP before the shell +is called and +.bP +output \fBenter_ca_mode\fP and +call \fBreset_prog_mode\fP after returning from the shell. +.PP +The \fBsetupterm\fP routine reads in the \fBterminfo\fP database, +initializing the \fBterminfo\fP structures, but does not set up the +output virtualization structures used by \fBcurses\fP. +These are its parameters: +.RS 3 +.TP 5 +\fIterm\fP +is the terminal type, a character string. +If \fIterm\fP is null, the environment variable \fBTERM\fP is used. +.TP 5 +\fIfiledes\fP +is the file descriptor used for all output. +.TP 5 +\fIerrret\fP +points to an optional location where an error status can be returned to +the caller. +If \fIerrret\fP is not null, +then \fBsetupterm\fP returns \fBOK\fP or +\fBERR\fP and stores a status value in the integer pointed to by +\fIerrret\fP. +A return value of \fBOK\fP combined with status of \fB1\fP in \fIerrret\fP +is normal. +.IP +If \fBERR\fP is returned, examine \fIerrret\fP: +.RS +.TP 5 +.B 1 +means that the terminal is hardcopy, cannot be used for curses applications. +.IP +\fBsetupterm\fP determines if the entry is a hardcopy type by +checking the \fBhc\fP (\fBhardcopy\fP) capability. +.TP 5 +.B 0 +means that the terminal could not be found, +or that it is a generic type, +having too little information for curses applications to run. +.IP +\fBsetupterm\fP determines if the entry is a generic type by +checking the \fBgn\fP (\fBgeneric\fP) capability. +.TP 5 +.B \-1 +means that the \fBterminfo\fP database could not be found. +.RE +.IP +If \fIerrret\fP is +null, \fBsetupterm\fP prints an error message upon finding an error +and exits. +Thus, the simplest call is: +.sp + \fBsetupterm((char *)0, 1, (int *)0);\fP, +.sp +which uses all the defaults and sends the output to \fBstdout\fP. +.RE +.\" *************************************************************************** +.SS The Terminal State +.PP +The \fBsetupterm\fP routine stores its information about the terminal +in a \fBTERMINAL\fP structure pointed to by the global variable \fBcur_term\fP. +If it detects an error, +or decides that the terminal is unsuitable (hardcopy or generic), +it discards this information, +making it not available to applications. +.PP +If \fBsetupterm\fP is called repeatedly for the same terminal type, +it will reuse the information. +It maintains only one copy of a given terminal's capabilities in memory. +If it is called for different terminal types, +\fBsetupterm\fP allocates new storage for each set of terminal capabilities. +.PP +The \fBset_curterm\fP routine sets \fBcur_term\fP to +\fInterm\fP, and makes all of the \fBterminfo\fP boolean, numeric, and +string variables use the values from \fInterm\fP. +It returns the old value of \fBcur_term\fP. +.PP +The \fBdel_curterm\fP routine frees the space pointed to by +\fIoterm\fP and makes it available for further use. +If \fIoterm\fP is +the same as \fBcur_term\fP, references to any of the \fBterminfo\fP +boolean, numeric, and string variables thereafter may refer to invalid +memory locations until another \fBsetupterm\fP has been called. +.PP +The \fBrestartterm\fP routine is similar to \fBsetupterm\fP and \fBinitscr\fP, +except that it is called after restoring memory to a previous state (for +example, when reloading a game saved as a core image dump). +\fBrestartterm\fP assumes that the windows and the input and output options +are the same as when memory was saved, +but the terminal type and baud rate may be different. +Accordingly, \fBrestartterm\fP saves various tty state bits, +calls \fBsetupterm\fP, and then restores the bits. +.\" *************************************************************************** +.SS Formatting Output +.PP +The \fBtparm\fP routine instantiates the string \fIstr\fP with +parameters \fIpi\fP. A pointer is returned to the result of \fIstr\fP +with the parameters applied. +Application developers should keep in mind these quirks of the interface: +.bP +Although \fBtparm\fP's actual parameters may be integers or strings, +the prototype expects \fBlong\fP (integer) values. +.bP +Aside from the \fBset_attributes\fP (\fBsgr\fP) capability, +most terminal capabilities require no more than one or two parameters. +.bP +Padding information is ignored by \fBtparm\fP; +it is interpreted by \fBtputs\fP. +.bP +The capability string is null-terminated. +Use \*(``\\200\*('' where an ASCII NUL is needed in the output. +.PP +\fBtiparm\fP is a newer form of \fBtparm\fP which uses \fI<stdarg.h>\fP +rather than a fixed-parameter list. +Its numeric parameters are integers (int) rather than longs. +.PP +Both \fBtparm\fP and \fBtiparm\fP assume that the application passes +parameters consistent with the terminal description. +Two extensions are provided as alternatives to deal with untrusted data: +.bP +\fBtiparm_s\fP is an extension which is a safer formatting function +than \fBtparm\fR or \fBtiparm\fR, +because it allows the developer to tell the curses +library how many parameters to expect in the parameter list, +and which may be string parameters. +.IP +The \fImask\fP parameter has one bit set for each of the parameters +(up to 9) which will be passed as char* rather than numbers. +.bP +The extension \fBtiscan_s\fP allows the application +to inspect a formatting capability to see what the curses library would assume. +.\" *************************************************************************** +.SS Output Functions +.PP +The \fBtputs\fP routine applies padding information +(i.e., by interpreting marker embedded in the terminfo capability +such as \*(``$<5>\*('' as 5 milliseconds) +to the string +\fIstr\fP and outputs it: +.bP +The \fIstr\fP parameter must be a terminfo string +variable or the return value from +\fBtparm\fP, \fBtiparm\fP, \fBtgetstr\fP, or \fBtgoto\fP. +.IP +The \fBtgetstr\fP and \fBtgoto\fP functions are part of the \fItermcap\fP +interface, +which happens to share this function name with the \fIterminfo\fP interface. +.bP +\fIaffcnt\fP is the number of lines affected, or 1 if +not applicable. +.bP +\fIputc\fP is a \fBputchar\fP-like routine to which +the characters are passed, one at a time. +.PP +The \fBputp\fR routine calls \fBtputs(\fIstr\fB, 1, putchar)\fR. +The output of \fBputp\fP always goes to \fBstdout\fP, rather than +the \fIfiledes\fP specified in \fBsetupterm\fP. +.PP +The \fBvidputs\fP routine displays the string on the terminal in the +video attribute mode \fIattrs\fP, which is any combination of the +attributes listed in \fBcurses\fP(3X). +The characters are passed to +the \fBputchar\fP-like routine \fIputc\fP. +.PP +The \fBvidattr\fP routine is like the \fBvidputs\fP routine, except +that it outputs through \fBputchar\fP. +.PP +The \fBvid_attr\fP and \fBvid_puts\fP routines correspond +to vidattr and vidputs, respectively. +They use a set of arguments for representing the video attributes plus color, +i.e., +.bP +\fIattrs\fP of type \fBattr_t\fP for the attributes and +.bP +\fIpair\fP of type \fBshort\fP for the color-pair number. +.PP +The \fBvid_attr\fP and \fBvid_puts\fP routines +are designed to use the attribute constants with the \fBWA_\fP prefix. +.PP +X/Open Curses reserves the \fIopts\fP argument for future use, +saying that applications must provide a null pointer for that argument. +As an extension, +this implementation allows \fIopts\fP to be used as a pointer to \fBint\fP, +which overrides the \fIpair\fP (\fBshort\fP) argument. +.PP +The \fBmvcur\fP routine provides low-level cursor motion. +It takes effect immediately (rather than at the next refresh). +.PP +While \fBputp\fP and \fBmvcur\fP are low-level functions which +do not use the high-level curses state, +they are declared in \fB<curses.h>\fP because SystemV did this +(see \fIHISTORY\fP). +.\" *************************************************************************** +.SS Terminal Capability Functions +.PP +The \fBtigetflag\fP, \fBtigetnum\fP and \fBtigetstr\fP routines return +the value of the capability corresponding to the \fBterminfo\fP +\fIcapname\fP passed to them, such as \fBxenl\fP. +The \fIcapname\fP for each capability is given in the table column entitled +\fIcapname\fP code in the capabilities section of \fBterminfo\fP(\*n). +.PP +These routines return special values to denote errors. +.PP +The \fBtigetflag\fP routine returns +.TP +\fB\-1\fP +if \fIcapname\fP is not a boolean capability, +or +.TP +\fB0\fP +if it is canceled or absent from the terminal description. +.PP +The \fBtigetnum\fP routine returns +.TP +\fB\-2\fP +if \fIcapname\fP is not a numeric capability, or +.TP +\fB\-1\fP +if it is canceled or absent from the terminal description. +.PP +The \fBtigetstr\fP routine returns +.TP +\fB(char *)\-1\fP +if \fIcapname\fP is not a string capability, +or +.TP +\fB0\fP +if it is canceled or absent from the terminal description. +.\" *************************************************************************** +.SS Terminal Capability Names +.PP +These null-terminated arrays contain +.bP +the short terminfo names (\*(``codes\*(''), +.bP +the \fBtermcap\fP names (\*(``names\*(''), and +.bP +the long terminfo names (\*(``fnames\*('') +.PP +for each of the predefined \fBterminfo\fP variables: +.sp +.RS +\fBconst char *boolnames[]\fP, \fB*boolcodes[]\fP, \fB*boolfnames[]\fP +.br +\fBconst char *numnames[]\fP, \fB*numcodes[]\fP, \fB*numfnames[]\fP +.br +\fBconst char *strnames[]\fP, \fB*strcodes[]\fP, \fB*strfnames[]\fP +.RE +.\" *************************************************************************** +.SS Releasing Memory +Each successful call to \fBsetupterm\fP allocates memory to hold the terminal +description. +As a side-effect, it sets \fBcur_term\fP to point to this memory. +If an application calls +.sp + \fBdel_curterm(cur_term);\fP +.sp +the memory will be freed. +.PP +The formatting functions \fBtparm\fP and \fBtiparm\fP extend the storage +allocated by \fBsetupterm\fP: +.bP +the \*(``static\*('' terminfo variables [a-z]. +Before ncurses 6.3, those were shared by all screens. +With ncurses 6.3, those are allocated per screen. +See \fBterminfo\fP(\*n) for details. +.bP +to improve performance, ncurses 6.3 caches the result of analyzing terminfo +strings for their parameter types. +That is stored as a binary tree referenced from the \fBTERMINAL\fP structure. +.PP +The higher-level \fBinitscr\fP and \fBnewterm\fP functions use \fBsetupterm\fP. +Normally they do not free this memory, but it is possible to do that using +the \fBdelscreen\fP(3X) function. +.\" *************************************************************************** +.SH RETURN VALUE +Routines that return an integer return \fBERR\fP upon failure and \fBOK\fP +(SVr4 only specifies \*(``an integer value other than \fBERR\fP\*('') +upon successful completion, +unless otherwise noted in the preceding routine descriptions. +.PP +Routines that return pointers always return \fBNULL\fP on error. +.PP +X/Open defines no error conditions. +In this implementation +.RS 3 +.TP 5 +\fBdel_curterm\fP +returns an error +if its terminal parameter is null. +.TP 5 +\fBputp\fP +calls \fBtputs\fP, returning the same error-codes. +.TP 5 +\fBrestartterm\fP +returns an error +if the associated call to \fBsetupterm\fP returns an error. +.TP 5 +\fBsetupterm\fP +returns an error +if it cannot allocate enough memory, or +create the initial windows (stdscr, curscr, newscr). +Other error conditions are documented above. +.TP 5 +\fBtparm\fP +returns a null if the capability would require unexpected parameters, +e.g., too many, too few, or incorrect types +(strings where integers are expected, or vice versa). +.TP 5 +\fBtputs\fP +returns an error if the string parameter is null. +It does not detect I/O errors: +X/Open states that \fBtputs\fP ignores the return value +of the output function \fIputc\fP. +.RE +.\" *************************************************************************** +.SS Compatibility macros +This implementation provides a few macros for compatibility with systems +before SVr4 (see \fIHISTORY\fP). +Those include +\fBcrmode\fP, +\fBfixterm\fP, +\fBgettmode\fP, +\fBnocrmode\fP, +\fBresetterm\fP, +\fBsaveterm\fP, and +\fBsetterm\fP. +.PP +In SVr4, those are found in \fB<curses.h>\fP, +but except for \fBsetterm\fP, are likewise macros. +The one function, \fBsetterm\fP, is mentioned in the manual page. +The manual page notes that the \fBsetterm\fP routine +was replaced by \fBsetupterm\fP, stating that the call: +.sp + \fBsetupterm(\fIterm\fB, 1, (int *)0)\fR +.sp +provides the same functionality as \fBsetterm(\fIterm\fB)\fR, +and is not recommended for new programs. +This implementation provides each of those symbols +as macros for BSD compatibility, +.\" *************************************************************************** +.SH HISTORY +.PP +SVr2 introduced the terminfo feature. +Its programming manual mentioned these low-level functions: +.TS +l l +_ _ +l l. +\fBFunction\fP \fBDescription\fP +fixterm restore tty to \*(``in curses\*('' state +gettmode establish current tty modes +mvcur low level cursor motion +putp T{ +utility function that uses \fBtputs\fP to send characters via \fBputchar\fP. +T} +resetterm set tty modes to \*(``out of curses\*('' state +resetty reset tty flags to stored value +saveterm save current modes as \*(``in curses\*('' state +savetty store current tty flags +setterm establish terminal with given type +setupterm establish terminal with given type +tparm instantiate a string expression with parameters +tputs apply padding information to a string +vidattr like \fBvidputs\fP, but outputs through \fBputchar\fP +vidputs T{ +output a string to put terminal in a specified video attribute mode +T} +.TE +.PP +The programming manual also mentioned +functions provided for termcap compatibility +(commenting that they \*(``may go away at a later date\*(''): +.TS +l l +_ _ +l l. +\fBFunction\fP \fBDescription\fP +tgetent look up termcap entry for given \fIname\fP +tgetflag get boolean entry for given \fIid\fP +tgetnum get numeric entry for given \fIid\fP +tgetstr get string entry for given \fIid\fP +tgoto apply parameters to given capability +tputs T{ +apply padding to capability, calling a function to put characters +T} +.TE +.PP +Early terminfo programs obtained capability values from the +\fBTERMINAL\fP structure initialized by \fBsetupterm\fP. +.PP +SVr3 extended terminfo by adding functions to retrieve capability values +(like the termcap interface), +and reusing tgoto and tputs: +.TS +l l +_ _ +l l. +\fBFunction\fP \fBDescription\fP +tigetflag get boolean entry for given \fIid\fP +tigetnum get numeric entry for given \fIid\fP +tigetstr get string entry for given \fIid\fP +.TE +.PP +SVr3 also replaced several of the SVr2 terminfo functions +which had no counterpart in the termcap interface, +documenting them as obsolete: +.TS +l l +_ _ +l l. +\fBFunction\fP \fBReplaced by\fP +crmode cbreak +fixterm reset_prog_mode +gettmode N/A +nocrmode nocbreak +resetterm reset_shell_mode +saveterm def_prog_mode +setterm setupterm +.TE +.PP +SVr3 kept the \fBmvcur\fP, \fBvidattr\fP and \fBvidputs\fP functions, +along with \fBputp\fP, \fBtparm\fP and \fBtputs\fP. +The latter were needed to support padding, +and handling functions such as \fBvidattr\fP +(which used more than the two parameters supported by \fBtgoto\fP). +.PP +SVr3 introduced the functions for switching between terminal +descriptions, e.g., \fBset_curterm\fP. +Some of that was incremental improvements to the SVr2 library: +.bP +The \fBTERMINAL\fP type definition was introduced in SVr3.01, +for the \fBterm\fP structure provided in SVr2. +.bP +The various global variables such as \fBboolnames\fP were mentioned +in the programming manual at this point, +though the variables were provided in SVr2. +.PP +SVr4 added the \fBvid_attr\fP and \fBvid_puts\fP functions. +.PP +There are other low-level functions declared in the curses header files +on Unix systems, +but none were documented. +The functions marked \*(``obsolete\*('' remained in use +by the Unix \fBvi\fP(1) editor. +.SH PORTABILITY +.SS Extensions +The functions marked as extensions were designed for \fBncurses\fP(3X), +and are not found in SVr4 curses, 4.4BSD curses, +or any other previous version of curses. +.PP +.SS Legacy functions +.PP +X/Open notes that \fBvidattr\fP and \fBvidputs\fP may be macros. +.PP +The function \fBsetterm\fP is not described by X/Open and must +be considered non-portable. +All other functions are as described by X/Open. +.SS Legacy data +.PP +\fBsetupterm\fP copies the terminal name to the array \fBttytype\fP. +This is not part of X/Open Curses, but is assumed by some applications. +.PP +Other implementions may not declare the capability name arrays. +Some provide them without declaring them. +X/Open does not specify them. +.PP +Extended terminal capability names, e.g., as defined by \fBtic\ \-x\fP, +are not stored in the arrays described here. +.SS Output buffering +.PP +Older versions of \fBncurses\fP assumed that the file descriptor passed to +\fBsetupterm\fP from \fBinitscr\fP or \fBnewterm\fP uses buffered I/O, +and would write to the corresponding stream. +In addition to the limitation that the terminal was left in block-buffered +mode on exit (like System V curses), +it was problematic because \fBncurses\fP +did not allow a reliable way to cleanup on receiving SIGTSTP. +.PP +The current version (ncurses6) +uses output buffers managed directly by \fBncurses\fP. +Some of the low-level functions described in this manual page write +to the standard output. +They are not signal-safe. +The high-level functions in \fBncurses\fP use +alternate versions of these functions +using the more reliable buffering scheme. +.SS Function prototypes +.PP +The X/Open Curses prototypes are based on the SVr4 curses header declarations, +which were defined at the same time the C language was first standardized in +the late 1980s. +.bP +X/Open Curses uses \fBconst\fP less effectively than a later design might, +in some cases applying it needlessly to values are already constant, +and in most cases overlooking parameters which normally would use \fBconst\fP. +Using constant parameters for functions which do not use \fBconst\fP +may prevent the program from compiling. +On the other hand, \fIwritable strings\fP are an obsolescent feature. +.IP +As an extension, this implementation can be configured to change the +function prototypes to use the \fBconst\fP keyword. +The ncurses ABI 6 enables this feature by default. +.bP +X/Open Curses prototypes \fBtparm\fP with a fixed number of parameters, +rather than a variable argument list. +.IP +This implementation uses a variable argument list, but can be +configured to use the fixed-parameter list. +Portable applications should provide 9 parameters after the format; +zeroes are fine for this purpose. +.IP +In response to review comments by Thomas E. Dickey, +X/Open Curses Issue 7 proposed the \fBtiparm\fP function in mid-2009. +.IP +While \fBtiparm\fP is always provided in ncurses, +the older form is only available as a build-time configuration option. +If not specially configured, \fBtparm\fP is the same as \fBtiparm\fP. +.PP +Both forms of \fBtparm\fP have drawbacks: +.bP +Most of the calls to \fBtparm\fP use only one or two parameters. +Passing nine on each call is awkward. +.IP +Using \fBlong\fP for the numeric parameter type is a workaround +to make the parameter use the same amount of stack as a pointer. +That approach dates back to the mid-1980s, before C was standarized. +Since then, there is a standard +(and pointers are not required to fit in a long). +.bP +Providing the right number of parameters for a variadic function +such as \fBtiparm\fP can be a problem, in particular for string parameters. +However, only a few terminfo capabilities use string parameters +(e.g., the ones used for programmable function keys). +.IP +The ncurses library checks usage of these capabilities, +and returns an error if the capability mishandles string parameters. +But it cannot check if a calling program provides strings in the right +places for the \fBtparm\fP calls. +.IP +The \fBtput\fR(1) program checks its use of these capabilities with a table, +so that it calls \fBtparm\fP correctly. +.SS Special TERM treatment +.PP +If configured to use the terminal-driver, +e.g., for the MinGW port, +.bP +\fBsetupterm\fP interprets a missing/empty TERM variable as the +special value \*(``unknown\*(''. +.bP +\fBsetupterm\fP allows explicit use of the +the windows console driver by checking if $TERM is set to +\*(``#win32con\*('' or an abbreviation of that string. +.SS Other portability issues +.PP +In System V Release 4, \fBset_curterm\fP has an \fBint\fP return type and +returns \fBOK\fP or \fBERR\fP. We have chosen to implement the X/Open Curses +semantics. +.PP +In System V Release 4, the third argument of \fBtputs\fP has the type +\fBint (*putc)(char)\fP. +.PP +At least one implementation of X/Open Curses (Solaris) returns a value +other than \fBOK\fP/\fBERR\fP from \fBtputs\fP. +That returns the length of the string, and does no error-checking. +.PP +X/Open notes that after calling \fBmvcur\fP, the curses state may not match the +actual terminal state, and that an application should touch and refresh +the window before resuming normal curses calls. +Both \fBncurses\fP and System V Release 4 curses implement \fBmvcur\fP using +the SCREEN data allocated in either \fBinitscr\fP or \fBnewterm\fP. +So though it is documented as a terminfo function, +\fBmvcur\fP is really a curses function which is not well specified. +.PP +X/Open states that the old location must be given for \fBmvcur\fP. +This implementation allows the caller to use \-1's for the old ordinates. +In that case, the old location is unknown. +.SH SEE ALSO +\fBcurses\fP(3X), +\fBcurs_initscr\fP(3X), +\fBcurs_kernel\fP(3X), +\fBcurs_memleaks\fP(3X), +\fBcurs_termcap\fP(3X), +\fBcurs_variables\fP(3X), +\fBterm_variables\fP(3X), +\fBputc\fP(3), +\fBterminfo\fP(\*n) |