- 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.
+ These low-level functions must be called by programs that deal directly
+ with the terminfo database to handle certain terminal capabilities,
+ such as programming function keys. For all other functionality, curses
+ functions are more suitable and their use is recommended.
- None of these functions use (or are aware of) multibyte character
- strings such as UTF-8:
+ None of these functions use (or are aware of) multibyte character
+ strings such as UTF-8.
- o capability names use the POSIX portable character set
+ o Capability names and codes use the POSIX portable character set.
- o capability string values have no associated encoding; they are
+ o Capability string values have no associated encoding; they are
strings of 8-bit characters.
- 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 terminfo(5)].
+ 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
+ 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 this order) to get the
+ curses.h and term.h should be included (in that order) to get the
definitions for these strings, numbers, and flags.
- The terminfo variables lines and columns are initialized by setupterm
- as follows:
+ 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 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,
+ 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
+ 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)].
+ Parameterized strings should be passed through tparm to instantiate
+ them. All terminfo strings (including the output of tparm) should be
+ sent to the terminal device with tputs or putp. Call reset_shell_mode
+ to restore the terminal modes before exiting; see curs_kernel(3x).
- Programs which use cursor addressing should
+ Programs that 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
+ Programs that execute shell subprocesses should
- o call reset_shell_mode and output exit_ca_mode before the shell is
+ 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
+ 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:
+ setupterm reads in the terminfo database, initializing the terminfo
+ structures, but does not set up the output virtualization structures
+ used by curses. Its parameters follow.
term is the terminal type, a character string. If term is null, the
- environment variable TERM is used.
+ environment variable TERM is read.
filedes
- is the file descriptor used for getting and setting terminal
+ 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
+ Higher-level applications use newterm(3x) to initialize 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
+ 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:
+ If ERR is returned, examine errret:
- 1 means that the terminal is hardcopy, cannot be used for
- curses applications.
+ 1 means that the terminal is hardcopy, and cannot be used
+ for curses applications.
- setupterm determines if the entry is a hardcopy type by
- checking the hc (hardcopy) capability.
+ setupterm determines if the entry is a hardcopy type by
+ checking the hardcopy (hc) capability.
- 0 means that the terminal could not be found, or that it is
- a generic type, having too little information for curses
+ 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.
+ setupterm determines if the entry is a generic type by
+ checking the generic_type (gn) capability.
- -1 means that the terminfo database could not be found.
+ -1 means that the terminfo database could not be found.
- If errret is null, setupterm prints an error message upon
+ If errret is null, setupterm reports an error message upon
finding an error and exits. Thus, the simplest call is:
- setupterm((char*)0,1,(int*)0);,
+ 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
+ setupterm 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
+ 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's capabilities in memory. If it is called for different
+ terminal types, setupterm allocates new storage for each set of
terminal capabilities.
- The set_curterm routine 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.
+ 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.
- 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.
+ del_curterm 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.
+ restartterm 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 terminal 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:
+ tparm 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.
+ prototype expects long (integer) values.
o Aside from the set_attributes (sgr) capability, most terminal
capabilities require no more than one or two parameters.
@@ -266,105 +258,109 @@
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 integers (int) rather
- than longs.
+ 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:
+ 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
+ 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.
+ to 9) passed as char pointers rather than numbers.
o The extension tiscan_s allows the application to inspect a
- formatting capability to see what the curses library would assume.
+ formatting capability to see what the curses library would assume.
- The tputs routine applies padding information (i.e., by interpreting
- marker embedded in the terminfo capability such as "$<5>" as 5
- milliseconds) to the string str and outputs it:
+ 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.
+
+ tputs 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.
+ o The str parameter must be a terminfo string variable or the return
+ value of 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.
+ which happens to share these function names with the terminfo API.
- oaffcnt is the number of lines affected, or 1 if not applicable.
+ oaffcnt is the number of lines affected, or 1 if not applicable.
- oputc is a putchar-like routine to which the characters are passed,
+ oputc is a putchar-like function to which the characters are passed,
one at a time.
- The putp routine calls tputs(str,1,putchar). The output of putp
- always goes to stdout, rather than the filedes specified in setupterm.
+ If tputs processes a time-delay, it uses the delay_output(3x)
+ function, routing any resulting padding characters through this
+ function.
+
+ putp 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 routine
- putc.
+ vidputs 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.
+ vidattr is like vidputs, except that it outputs through putchar(3).
- The vid_attr and vid_puts routines correspond to vidattr and vidputs,
- respectively. They use a set of arguments for representing the video
- attributes plus color, i.e.,
+ 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
+ oattrs, of type attr_t, for the attributes and
- opair of type short for the color-pair number.
+ opair, of type short, for the color pair number.
- The vid_attr and vid_puts routines are designed to use the attribute
- constants with the WA_ prefix.
+ 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. As an
- extension, this implementation allows opts to be used as a pointer to
- int, which overrides the pair (short) argument.
+ 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).
+ mvcur 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 SystemV did
- this (see HISTORY).
+ While putp and mvcur are low-level functions that do not use high-level
+ curses state, ncurses declares them in curses.h because System V did
+ this (see section "HISTORY" below).
- 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).
+ tigetflag, tigetnum, and tigetstr return the value of the capability
+ corresponding to the terminfocap-code, such as xenl, passed to them.
+ The cap-code for each capability is given in the table column entitled
+ cap-code code in the capabilities section of terminfo(5).
- These routines return special values to denote errors.
+ These functions return special values to denote errors.
- The tigetflag routine returns
+ tigetflag returns
- -1 if capname is not a boolean capability, or
+ -1 if cap-code is not a Boolean capability, or
0 if it is canceled or absent from the terminal description.
- The tigetnum routine returns
+ tigetnum returns
- -2 if capname is not a numeric capability, or
+ -2 if cap-code is not a numeric capability, or
-1 if it is canceled or absent from the terminal description.
- The tigetstr routine returns
+ tigetstr returns
(char*)-1
- if capname is not a string capability, or
+ if cap-code is not a string capability, or
0 if it is canceled or absent from the terminal description.
@@ -372,13 +368,13 @@
These null-terminated arrays contain
- o the short terminfo names ("codes"),
+ o the short terminfo names ("codes"),
- o the termcap names ("names"), and
+ o the termcap names ("names"), and
- o the long terminfo names ("fnames")
+ o the long terminfo names ("fnames")
- for each of the predefined terminfo variables:
+ for each of the predefined terminfo variables:
constchar*boolnames[], *boolcodes[], *boolfnames[]constchar*numnames[], *numcodes[], *numfnames[]
@@ -387,23 +383,23 @@
Each successful call to setupterm allocates memory to hold the terminal
- description. As a side-effect, it sets cur_term to point to this
+ description. As a side effect, it sets cur_term to point to this
memory. If an application calls
- del_curterm(cur_term);
+ del_curterm(cur_term);
the memory will be freed.
The formatting functions tparm and tiparm extend the storage allocated
- by setupterm:
+ by setupterm as follows.
- 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 They add 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).
- 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.
+ 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
@@ -411,197 +407,112 @@
- 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.
-
- Routines that return pointers always return NULL on error.
-
- X/Open defines no error conditions. In this implementation
-
- 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, newscr). Other error
- conditions are documented above.
+ X/Open Curses defines no failure conditions. In ncurses,
- 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).
+ del_curtem
+ fails if its terminal parameter is null.
- tputs
- returns an error if the string parameter is null. It does not
- detect I/O errors: X/Open states that tputs ignores the return
- value of the output function putc.
+ putp calls tputs, returning the same error codes.
+ restartterm
+ fails if the associated call to setupterm returns an error.
-
- This implementation provides a few macros for compatibility with
- systems before SVr4 (see HISTORY). Those include crmode, fixterm,
- gettmode, nocrmode, resetterm, saveterm, and setterm.
+ setupterm
+ fails if it cannot allocate enough memory, or create the initial
+ windows (stdscr, curscr, and newscr) Other error conditions are
+ documented above.
- In SVr4, those are found in <curses.h>, but except for setterm, are
- likewise macros. The one function, setterm, is mentioned in the manual
- page. The manual page notes that the setterm routine was replaced by
- setupterm, stating that the call:
+ tparm
+ returns a null pointer if the capability would require unexpected
+ parameters; that is, too many, too few, or incorrect types
+ (strings where integers are expected, or vice versa).
- setupterm(term,1,(int*)0)
+ tputs
+ fails 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.
- provides the same functionality as setterm(term), and is not
- recommended for new programs. This implementation provides each of
- those symbols as macros for BSD compatibility,
+
+ 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.
-
- SVr2 introduced the terminfo feature. Its programming manual mentioned
- these low-level functions:
- FunctionDescription
- ------------------------------------------------------------
- fixterm restore tty to "in curses" state
-
- gettmode establish current tty modes
- mvcur low level cursor motion
- putp utility function that uses 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 instantiate a string expression with parameters
- tputs apply padding information to a string
- vidattr like vidputs, but outputs through putchar
- vidputs output a string to put terminal in a specified
- video attribute mode
-
- The programming manual also mentioned functions provided for termcap
- compatibility (commenting that they "may go away at a later date"):
+
+ 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.
- 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 apply padding to capability, calling
- a function to put characters
-
- Early terminfo programs obtained capability values from the TERMINAL
- structure initialized by setupterm.
-
- SVr3 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 which 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
- handling functions such as vidattr (which used more than the two
- parameters supported by tgoto).
-
- SVr3 introduced the functions for switching between terminal
- descriptions, e.g., set_curterm. Some of that was incremental
- improvements to the SVr2 library:
-
- o The TERMINAL type definition was introduced in SVr3.01, for the
- term structure provided in SVr2.
-
- o The various global variables such as boolnames were mentioned in
- the programming manual at this point, though the variables were
- provided in SVr2.
-
- SVr4 added the vid_attr and vid_puts functions.
-
- 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 vi(1) editor.
+ ncurses allows opts to be a pointer to int, which overrides the pair
+ (short) argument.
- The functions marked as extensions were designed for ncurses(3x), and
- are not found in SVr4 curses, 4.4BSD curses, or any other previous
- version of curses.
+ setterm is not described by X/Open and must be considered non-portable.
+ All other functions are as described by X/Open.
-
+ 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.
- The function setterm is not described by X/Open and must be considered
- non-portable. All other functions are as described by X/Open.
+ 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.
+ provide them without declaring them. X/Open Curses does not specify
+ them.
- Extended terminal capability names, e.g., as defined by tic-x, are not
+ 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 use alternate versions of these functions
+ 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 clean up 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, writablestrings are an obsolescent feature.
+ o X/Open Curses uses const less effectively than a later design
+ might, sometimes applying it needlessly to values that are already
+ constant, and in most cases overlooking parameters that normally
+ would use const. Passing const-qualified parameters to functions
+ that do not declare them 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
+ 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,
@@ -609,13 +520,13 @@
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.
+ should provide nine 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
+ 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.
@@ -624,75 +535,160 @@
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
+ 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).
+ 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).
+ parameters. However, only a few terminfo capabilities use string
+ parameters (for instance, 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
+ 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
+ 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, as with the MinGW port,
-
- If configured to use the terminal-driver, e.g., for the MinGW port,
-
- osetupterm interprets a missing/empty TERM variable as the special
+ osetupterm interprets a missing/empty TERM variable as the special
value "unknown".
- SVr4 curses uses the special value "dumb".
+ 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.
+ The difference between the two is that the former uses the
+ generic_type (gn) 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
+ 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 System V Release 4, the third argument of tputs has the type int
- (*putc)(char).
+ 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/ERR from tputs. That returns the length of the string,
- and does no error-checking.
+ 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 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, as with the cursor_address (cup) capability,
+ 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 terminal to "in curses" state
+ gettmode establish current terminal modes
+ mvcur low level cursor motion
+ putp use tputs to send characters via putchar
+ resetterm set terminal modes to "out of curses" state
+
+ resetty reset terminal flags to stored value
+ saveterm save current modes as "in curses" state
+ savetty store current terminal 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").
- 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.
+ 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.
- X/Open states that the old location must be given for mvcur. This
- implementation allows the caller to use -1's for the old ordinates. In
- that case, the old location is unknown.
+ 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.