- These low-level routines must be called by programs that
- have to deal directly with the terminfo database to handle
- certain terminal capabilities, such as programming func-
- tion keys. For all other functionality, curses routines
- are more suitable and their use is recommended.
-
- Initially, setupterm should be called. Note that
- setupterm is automatically called by initscr and newterm.
- This defines the set of terminal-dependent variables
- [listed in terminfo(5)]. The terminfo variables lines and
- columns are initialized by setupterm as follows: If
- use_env(FALSE) has been called, values for lines and
- columns specified in terminfo are used. Otherwise, if the
- environment variables LINES and COLUMNS exist, their val-
- ues 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 lines and columns specified in
- the terminfo database are used.
-
- The header files curses.h and term.h should be included
- (in this order) to get the definitions for these strings,
- numbers, and flags. Parameterized strings should be
- passed through tparm to instantiate them. All terminfo
- strings [including the output of tparm] should be printed
- with tputs or putp. Call the reset_shell_mode to restore
- the tty modes before exiting [see curs_kernel(3x)].
- Programs which use cursor addressing should output
- enter_ca_mode upon startup and should output exit_ca_mode
- before exiting. Programs desiring shell escapes should
- call
-
- reset_shell_mode and output exit_ca_mode before the shell
- is called and should output enter_ca_mode and call
- reset_prog_mode after returning from the shell.
-
- The setupterm routine reads in the terminfo database, ini-
- tializing the terminfo structures, but does not set up the
- output virtualization structures used by curses. The ter-
- minal type is the character string term; if term is null,
- the environment variable TERM is used. All output is to
- file descriptor fildes which is initialized for output.
- If errret is not null, then setupterm returns OK or ERR
- and stores a status value in the integer pointed to by
- errret. A return value of OK combined with status of 1 in
- errret is normal. If ERR is returned, examine errret:
-
- 1 means that the terminal is hardcopy, cannot be
- used for curses applications.
-
- 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.
-
- -1 means that the terminfo database could not be
- found.
-
- If errret is null, setupterm prints an error message upon
- finding an error and exits. Thus, the simplest call is:
-
- setupterm((char*)0,1,(int*)0);,
-
- which uses all the defaults and sends the output to std-
- out.
-
- The setterm routine is being replaced by setupterm. The
- call:
-
- setupterm(term,1,(int*)0)
-
- provides the same functionality as setterm(term). The
- setterm routine is included here for BSD compatibility,
- and is not recommended for new programs.
-
- The set_curterm routine sets the variable cur_term to
- nterm, and makes all of the terminfo boolean, numeric, and
- string variables use the values from nterm. It returns
- the old value of cur_term.
-
- The del_curterm routine frees the space pointed to by
- oterm and makes it available for further use. If oterm is
- the same as cur_term, references to any of the terminfo
- boolean, numeric, and string variables thereafter may
- refer to invalid memory locations until another setupterm
- has been called.
-
- The restartterm routine is similar to setupterm and
- initscr, except that it is called after restoring memory
- to a previous state (for example, when reloading a game
- saved as a core image dump). It assumes that the windows
- and the input and output options are the same as when mem-
- ory was saved, but the terminal type and baud rate may be
- different. Accordingly, it saves various tty state bits,
- does a setupterm, and then restores the bits.
-
- The tparm routine instantiates the string str with parame-
- ters pi. A pointer is returned to the result of str with
- the parameters applied.
-
- The tputs routine applies padding information to the
- string str and outputs it. The str must be a terminfo
- string variable or the return value from tparm, tgetstr,
- or tgoto. affcnt is the number of lines affected, or 1 if
- not applicable. putc is a putchar-like routine to which
- the characters are passed, one at a time.
-
- The putp routine calls tputs(str,1,putchar). Note that
- the output of putp always goes to stdout, not to the
- fildes specified in setupterm.
-
- The vidputs routine displays the string on the terminal in
- the video attribute mode attrs, which is any combination
- of the attributes listed in curses(3x). The characters
- are passed to the putchar-like routine putc.
-
- The vidattr routine is like the vidputs routine, except
- that it outputs through putchar.
-
- The mvcur routine provides low-level cursor motion. It
- takes effect immediately (rather than at the next
- refresh).
-
- The tigetflag, tigetnum and tigetstr routines return the
- value of the capability corresponding to the terminfocap-
- name passed to them, such as xenl.
-
- The tigetflag routine returns the value -1 if capname is
- not a boolean capability, or 0 if it is canceled or absent
- from the terminal description.
- The tigetnum routine returns the value -2 if capname is
- not a numeric capability, or -1 if it is canceled or
- absent from the terminal description.
+
+ #include<curses.h>
+ #include<term.h>
- The tigetstr routine returns the value (char*)-1 if
- capname is not a string capability, or 0 if it is canceled
- or absent from the terminal description.
+ TERMINAL*cur_term;
- The capname for each capability is given in the table col-
- umn entitled capname code in the capabilities section of
- terminfo(5).
+ constchar*constboolnames[];
+ constchar*constboolcodes[];
+ constchar*constboolfnames[];
+ constchar*constnumnames[];
+ constchar*constnumcodes[];
+ constchar*constnumfnames[];
+ constchar*conststrnames[];
+ constchar*conststrcodes[];
+ constchar*conststrfnames[];
- char*boolnames, *boolcodes, *boolfnames
+ intsetupterm(constchar*term,intfiledes,int*errret);
+ TERMINAL*set_curterm(TERMINAL*nterm);
+ intdel_curterm(TERMINAL*oterm);
+ intrestartterm(constchar*term,intfiledes,int*errret);
- char*numnames, *numcodes, *numfnames
+ char*tparm(constchar*str, ...);
+ /*or*/
+ char*tparm(constchar*str,longp1 ... longp9);
- char*strnames, *strcodes, *strfnames
+ inttputs(constchar*str,intaffcnt,int(*putc)(int));
+ intputp(constchar*str);
- These null-terminated arrays contain the capnames, the
- termcap codes, and the full C names, for each of the ter-
- minfo variables.
+ intvidputs(chtypeattrs,int(*putc)(int));
+ intvidattr(chtypeattrs);
+ intvid_puts(attr_tattrs,shortpair,void*opts,int(*putc)(int));
+ intvid_attr(attr_tattrs,shortpair,void*opts);
+ intmvcur(intoldrow,intoldcol,intnewrow,intnewcol);
-
-
RETURN VALUE
- Routines that return an integer return ERR upon failure
- and OK (SVr4 only specifies "an integer value other than
- ERR") upon successful completion, unless otherwise noted
- in the preceding routine descriptions.
+ inttigetflag(constchar*capname);
+ inttigetnum(constchar*capname);
+ char*tigetstr(constchar*capname);
- Routines that return pointers always return NULL on error.
+ char*tiparm(constchar*str, ...);
+ /*extensions*/
+ char*tiparm_s(intexpected,intmask,constchar*str,...);
+ inttiscan_s(int*expected,int*mask,constchar*str);
-
-
NOTES
- The setupterm routine should be used in place of setterm.
- It may be useful when you want to test for terminal capa-
- bilities without committing to the allocation of storage
- involved in initscr.
+ /*deprecated*/
+ intsetterm(constchar*term);
- Note that vidattr and vidputs may be macros.
+
+ These low-level routines must be called by programs that have to deal
+ directly with the terminfo database to handle certain terminal
+ capabilities, such as programming function keys. For all other
+ functionality, curses routines are more suitable and their use is
+ recommended.
-
-
PORTABILITY
- The function setterm is not described in the XSI Curses
- standard and must be considered non-portable. All other
- functions are as described in the XSI curses standard.
+ None of these functions use (or are aware of) multibyte character
+ strings such as UTF-8.
- In System V Release 4, set_curterm has an int return type
- and returns OK or ERR. We have chosen to implement the
- XSI Curses semantics.
+ o Capability names and codes use the POSIX portable character set.
- In System V Release 4, the third argument of tputs has the
- type int(*putc)(char).
+ o Capability string values have no associated encoding; they are
+ strings of 8-bit characters.
- The XSI Curses standard prototypes tparm with a fixed num-
- ber of parameters, rather than a variable argument list.
- XSI notes that after calling mvcur, the curses state may
- not match the actual terminal state, and that an applica-
- tion should touch and refresh the window before resuming
- normal curses calls. Both ncurses and System V Release 4
- curses implement mvcur using the SCREEN data allocated in
- either initscr or newterm. So though it is documented as
- a terminfo function, mvcur is really a curses function
- which is not well specified.
+
+ Initially, setupterm should be called. The high-level curses functions
+ initscr and newterm call setupterm to initialize the low-level set of
+ terminal-dependent variables listed in term_variables(3x).
+ Applications can use the terminal capabilities either directly (via
+ header definitions), or by special functions. The header files
+ curses.h and term.h should be included (in that order) to get the
+ definitions for these strings, numbers, and flags.
-
-
SEE ALSO
- curses(3x), curs_initscr(3x), curs_kernel(3x), curs_term-
- cap(3x), putc(3S), terminfo(5)
+ The terminfo variables lines and columns are initialized by setupterm
+ as follows:
+
+ o If use_env(FALSE) has been called, values for lines and columns
+ specified in terminfo are used.
+
+ o Otherwise, if the environment variables LINES and COLUMNS 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 lines and columns specified in the terminfo database are
+ used.
+
+ Parameterized strings should be passed through tparm to instantiate
+ them. All terminfo strings (including the output of tparm) should be
+ printed with tputs or putp. Call reset_shell_mode to restore the tty
+ modes before exiting [see curs_kernel(3x)].
+
+ Programs which use cursor addressing should
+
+ o output enter_ca_mode upon startup and
+
+ o output exit_ca_mode before exiting.
+
+ Programs which execute shell subprocesses should
+
+ o call reset_shell_mode and output exit_ca_mode before the shell is
+ called and
+
+ o output enter_ca_mode and call reset_prog_mode after returning from
+ the shell.
+
+ The setupterm routine reads in the terminfo database, initializing the
+ terminfo structures, but does not set up the output virtualization
+ structures used by curses. These are its parameters:
+
+ term is the terminal type, a character string. If term is null, the
+ environment variable TERM is used.
+
+ filedes
+ is the file descriptor used for getting and setting terminal
+ I/O modes.
+
+ Higher-level applications use newterm(3x) for initializing the
+ terminal, passing an output stream rather than a descriptor.
+ In curses, the two are the same because newterm calls
+ setupterm, passing the file descriptor derived from its output
+ stream parameter.
+
+ errret
+ points to an optional location where an error status can be
+ returned to the caller. If errret is not null, then setupterm
+ returns OK or ERR and stores a status value in the integer
+ pointed to by errret. A return value of OK combined with
+ status of 1 in errret is normal.
+
+ If ERR is returned, examine errret:
+
+ 1 means that the terminal is hardcopy, cannot be used for
+ curses applications.
+
+ setupterm determines if the entry is a hardcopy type by
+ checking the hc (hardcopy) capability.
+
+ 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.
+
+ setupterm determines if the entry is a generic type by
+ checking the gn (generic_type) capability.
+
+ -1 means that the terminfo database could not be found.
+
+ If errret is null, setupterm prints an error message upon
+ finding an error and exits. Thus, the simplest call is:
+
+ setupterm((char*)0,1,(int*)0);
+
+ which uses all the defaults and sends the output to stdout.
+
+
+
+ The setupterm routine stores its information about the terminal in a
+ TERMINAL structure pointed to by the global variable cur_term. 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.
+
+ If setupterm 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, setupterm allocates new storage for each set of
+ terminal capabilities.
+
+ set_curterm sets cur_term to nterm, and makes all of the terminfo
+ Boolean, numeric, and string variables use the values from nterm. It
+ returns the old value of cur_term.
+
+ del_curterm routine frees the space pointed to by oterm and makes it
+ available for further use. If oterm is the same as cur_term,
+ references to any of the terminfo Boolean, numeric, and string
+ variables thereafter may refer to invalid memory locations until
+ another setupterm has been called.
+
+ The restartterm routine is similar to setupterm and initscr, except
+ that it is called after restoring memory to a previous state (for
+ example, when reloading a game saved as a core image dump).
+ restartterm 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, restartterm saves various tty
+ state bits, calls setupterm, and then restores the bits.
+
+
+
+ The tparm routine instantiates the string str with parameters pi. A
+ pointer is returned to the result of str with the parameters applied.
+ Application developers should keep in mind these quirks of the
+ interface:
+
+ o Although tparm's actual parameters may be integers or strings, the
+ prototype expects long (integer) values.
+
+ o Aside from the set_attributes (sgr) capability, most terminal
+ capabilities require no more than one or two parameters.
+
+ o Padding information is ignored by tparm; it is interpreted by
+ tputs.
+
+ o The capability string is null-terminated. Use "\200" where an
+ ASCII NUL is needed in the output.
+
+ tiparm is a newer form of tparm which uses stdarg.h rather than a
+ fixed-parameter list. Its numeric parameters are ints rather than
+ longs.
+
+ Both tparm and tiparm assume that the application passes parameters
+ consistent with the terminal description. Two extensions are provided
+ as alternatives to deal with untrusted data:
+
+ otiparm_s is an extension which is a safer formatting function than
+ tparm or tiparm, 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.
+
+ The mask parameter has one bit set for each of the parameters (up
+ to 9) which will be passed as char* rather than numbers.
+
+ o The extension tiscan_s allows the application to inspect a
+ formatting capability to see what the curses library would assume.
+
+
+
+ String capabilities can contain padding information, a time delay
+ (accommodating performance limitations of hardware terminals) expressed
+ as $<n>, where n is a nonnegative integral count of milliseconds. If n
+ exceeds 30,000 (thirty seconds), it is capped at that value.
+
+ The tputs routine interprets time-delay information in the string str
+ and outputs it, executing the delays:
+
+ o The str parameter must be a terminfo string variable or the return
+ value from tparm, tiparm, tgetstr, or tgoto.
+
+ The tgetstr and tgoto functions are part of the termcap interface,
+ which happens to share this function name with the terminfo
+ interface.
+
+ oaffcnt is the number of lines affected, or 1 if not applicable.
+
+ oputc is a putchar-like function to which the characters are passed,
+ one at a time.
+
+ If tputs processes a time-delay, it uses the delay_output(3x)
+ function, routing any resulting padding characters through this
+ function.
+
+ The putp routine calls tputs(str,1,putchar). The output of putp
+ always goes to stdout, rather than the filedes specified in setupterm.
+
+ The vidputs routine displays the string on the terminal in the video
+ attribute mode attrs, which is any combination of the attributes listed
+ in curses(3x). The characters are passed to the putchar-like function
+ putc.
+
+ The vidattr routine is like the vidputs routine, except that it outputs
+ through putchar.
+
+ vid_attr and vid_puts correspond to vidattr and vidputs, respectively.
+ They use multiple parameters to represent the character attributes and
+ color; namely,
+
+ oattrs, of type attr_t, for the attributes and
+
+ opair, of type short, for the color pair number.
+
+ Use the attribute constants prefixed with "WA_" with vid_attr and
+ vid_puts.
+
+ X/Open Curses reserves the opts argument for future use, saying that
+ applications must provide a null pointer for that argument; but see
+ section "EXTENSIONS" below.
+
+ The mvcur routine provides low-level cursor motion. It takes effect
+ immediately (rather than at the next refresh). Unlike the other low-
+ level output functions, which either write to the standard output or
+ pass an output function parameter, mvcur uses an output file descriptor
+ derived from the output stream parameter of newterm(3x).
+
+ While putp and mvcur are low-level functions which do not use the high-
+ level curses state, they are declared in curses.h because System V did
+ this (see HISTORY).
+
+
+
+ The tigetflag, tigetnum and tigetstr routines return the value of the
+ capability corresponding to the terminfocapname passed to them, such
+ as xenl. The capname for each capability is given in the table column
+ entitled capname code in the capabilities section of terminfo(5).
+
+ These routines return special values to denote errors.
+
+ The tigetflag routine returns
+
+ -1 if capname is not a Boolean capability, or
+
+ 0 if it is canceled or absent from the terminal description.
+
+ The tigetnum routine returns
+
+ -2 if capname is not a numeric capability, or
+
+ -1 if it is canceled or absent from the terminal description.
+ The tigetstr routine returns
+ (char*)-1
+ if capname is not a string capability, or
+ 0 if it is canceled or absent from the terminal description.
+
+ These null-terminated arrays contain
+ o the short terminfo names ("codes"),
+ o the termcap names ("names"), and
+ o the long terminfo names ("fnames")
+ for each of the predefined terminfo variables:
+ constchar*boolnames[], *boolcodes[], *boolfnames[]
+ constchar*numnames[], *numcodes[], *numfnames[]
+ constchar*strnames[], *strcodes[], *strfnames[]
+
+ Each successful call to setupterm allocates memory to hold the terminal
+ description. As a side-effect, it sets cur_term to point to this
+ memory. If an application calls
+ del_curterm(cur_term);
+ the memory will be freed.
+ The formatting functions tparm and tiparm extend the storage allocated
+ by setupterm:
+ o 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 terminfo(5) for details.
+ o 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 TERMINAL structure.
+ The higher-level initscr and newterm functions use setupterm. Normally
+ they do not free this memory, but it is possible to do that using the
+ delscreen(3x) function.
+
+ X/Open defines no failure conditions. In ncurses,
+ del_curterm
+ returns an error if its terminal parameter is null.
+ putp calls tputs, returning the same error-codes.
+ restartterm
+ returns an error if the associated call to setupterm returns an
+ error.
+ setupterm
+ returns an error if it cannot allocate enough memory, or create
+ the initial windows (stdscr, curscr, and newscr) Other error
+ conditions are documented above.
+ tparm
+ 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).
+ tputs
+ returns an error if the string parameter is null. It does not
+ detect I/O errors: X/Open Curses states that tputs ignores the
+ return value of the output function putc.
+
+ The vid_attr function in ncurses is a special case. It was originally
+ implemented based on a draft of X/Open Curses, as a macro, before other
+ parts of the ncurses wide-character API were developed, and unlike the
+ other wide-character functions, is also provided in the non-wide-
+ character configuration.
+
+ The functions marked as extensions were designed for ncurses, and are
+ not found in SVr4 curses, 4.4BSD curses, or any other previous curses
+ implementation.
+ ncurses allows opts to be a pointer to int, which overrides the pair
+ (short) argument.
+
+ This implementation provides a few macros for compatibility with
+ systems before SVr4 (see section "HISTORY" below). They include
+ Bcrmode, Bfixterm, Bgettmode, Bnocrmode, Bresetterm, Bsaveterm, and
+ Bsetterm.
+ In SVr4, these are found in curses.h, but except for setterm, are
+ likewise macros. The one function, setterm, is mentioned in the manual
+ page. It further notes that setterm was replaced by setupterm, stating
+ that the call
+ setupterm(term, 1, (int *)0)
+ provides the same functionality as setterm(term), discouraging the
+ latter for new programs. ncurses implements each of these symbols as
+ macros for BSD curses compatibility.
+
+ setupterm copies the terminal name to the array ttytype. This is not
+ part of X/Open Curses, but is assumed by some applications.
+ Other implementions may not declare the capability name arrays. Some
+ provide them without declaring them. X/Open does not specify them.
+ Extended terminal capability names, as defined by "tic-x", are not
+ stored in the arrays described here.
+
+ Older versions of ncurses assumed that the file descriptor passed to
+ setupterm from initscr or newterm 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 ncurses did not allow a reliable
+ way to cleanup on receiving SIGTSTP.
+ The current version (ncurses6) uses output buffers managed directly by
+ ncurses. 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 ncurses employ alternate versions of these functions
+ using the more reliable buffering scheme.
+
+ 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.
+ o X/Open Curses uses const 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 const. Using constant parameters for functions which do
+ not use const may prevent the program from compiling. On the other
+ hand, "writable strings" are an obsolescent feature.
+ As an extension, this implementation can be configured to change
+ the function prototypes to use the const keyword. The ncurses ABI
+ 6 enables this feature by default.
+ o X/Open Curses prototypes tparm with a fixed number of parameters,
+ rather than a variable argument list.
+
+ 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.
+
+ In response to review comments by Thomas E. Dickey, X/Open Curses
+ Issue 7 proposed the tiparm function in mid-2009.
+
+ While tiparm is always provided in ncurses, the older form is only
+ available as a build-time configuration option. If not specially
+ configured, tparm is the same as tiparm.
+
+ Both forms of tparm have drawbacks:
+
+ o Most of the calls to tparm use only one or two parameters. Passing
+ nine on each call is awkward.
+
+ Using long 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 standardized.
+ Since then, there is a standard (and pointers are not required to
+ fit in a long).
+
+ o Providing the right number of parameters for a variadic function
+ such as tiparm 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).
+
+ 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 tparm calls.
+
+ The tput(1) program checks its use of these capabilities with a
+ table, so that it calls tparm correctly.
+
+ SpecialTERMtreatment
+ If configured to use the terminal-driver, e.g., for the MinGW port,
+
+ osetupterm interprets a missing/empty TERM variable as the special
+ value "unknown".
+
+ SVr4 curses uses the special value "dumb".
+
+ The difference between the two is that the former uses the gn (-
+ generic_type) terminfo capability, while the latter does not. A
+ generic terminal is unsuitable for full-screen applications.
+
+ osetupterm allows explicit use of the the windows console driver by
+ checking if $TERM is set to "#win32con" or an abbreviation of that
+ string.
+
+
+
+ In SVr4, set_curterm returns an int,OK or ERR. We have chosen to
+ implement the X/Open Curses semantics.
+
+ In SVr4, the third argument of tputs has the type "int(*putc)(char)".
+
+ At least one implementation of X/Open Curses (Solaris) returns a value
+ other than OK or ERR from tputs. It instead returns the length of the
+ string, and does no error checking.
+
+ X/Open Curses notes that after calling mvcur, 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
+ ncurses and SVr4 curses implement mvcur using the SCREEN data allocated
+ in either initscr or newterm. So though it is documented as a terminfo
+ function, mvcur is really a curses function that is not well specified.
+
+ X/Open notes that after calling mvcur, 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 ncurses
+ and System V Release 4 curses implement mvcur using the SCREEN data
+ allocated in either initscr or newterm. So though it is documented as
+ a terminfo function, mvcur is really a curses function which is not
+ well specified.
+
+ X/Open Curses states that the old location must be given for mvcur to
+ accommodate terminals that lack absolute cursor positioning. ncurses
+ allows the caller to use -1 for either or both old coordinates. The -1
+ tells ncurses that the old location is unknown, and that it must use
+ only absolute motion (such as cursor_address) rather than the least
+ costly combination of absolute and relative motion.
+
+
+
+ SVr2 (1984) introduced the terminfo feature. Its programming manual
+ mentioned the following low-level functions.
+
+ FunctionDescription
+ ------------------------------------------------------------------------
+ fixterm restore tty to "in curses" state
+ gettmode establish current tty modes
+ mvcur low level cursor motion
+ putp use tputs to send characters via putchar
+ 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 interpolate parameters into string capability
+ tputs apply padding information to a string
+ vidattr like vidputs, but output through putchar
+ vidputs write string to terminal, applying specified attributes
+
+ The programming manual also mentioned functions provided for termcap
+ compatibility (commenting that they "may go away at a later date").
+
+ FunctionDescription
+ ------------------------------------------------------------------------
+ tgetent look up termcap entry for given name
+ tgetflag get Boolean entry for given id
+ tgetnum get numeric entry for given id
+ tgetstr get string entry for given id
+ tgoto apply parameters to given capability
+ tputs write characters via a function parameter, applying padding
+
+ Early terminfo programs obtained capability values from the TERMINAL
+ structure initialized by setupterm.
+
+ SVr3 (1987) extended terminfo by adding functions to retrieve
+ capability values (like the termcap interface), and reusing tgoto and
+ tputs.
+
+ FunctionDescription
+ ------------------------------------------------------------------------
+ tigetflag get Boolean entry for given id
+ tigetnum get numeric entry for given id
+ tigetstr get string entry for given id
+
+ SVr3 also replaced several of the SVr2 terminfo functions that had no
+ counterpart in the termcap interface, documenting them as obsolete.
+
+ FunctionReplacedby
+ ------------------------------------------------------------------------
+ crmode cbreak
+ fixterm reset_prog_mode
+ gettmode n/a
+ nocrmode nocbreak
+ resetterm reset_shell_mode
+ saveterm def_prog_mode
+ setterm setupterm
+
+ SVr3 kept the mvcur, vidattr, and vidputs functions, along with putp,
+ tparm, and tputs. The latter were needed to support padding, and to
+ handle capabilities accessed by functions such as vidattr (which used
+ more than the two parameters supported by tgoto).
+
+ SVr3 introduced the functions for switching between terminal
+ descriptions; for example, set_curterm. Some changes reflected
+ incremental improvements to the SVr2 library.
+
+ o The TERMINAL type definition was introduced in SVr3.01, for the
+ term structure provided in SVr2.
+
+ o Various global variables such as boolnames were mentioned in the
+ programming manual at this point, though the variables had been
+ provided in SVr2.
+
+ SVr4 (1989) added the vid_attr and vid_puts functions.
+
+ Other low-level functions are declared in the curses header files of
+ Unix systems, but none are documented. Those noted as "obsolete" by
+ SVr3 remained in use by System V's vi(1) editor.
+
+
+