- 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.
-
- Initialization
- Initially, setupterm should be called. Note that se-
- tupterm is automatically called by initscr and newterm.
- This defines the set of terminal-dependent variables
- [listed in terminfo(5)].
-
- Each initialization routine provides applications with the
- terminal capabilities either directly (via header defini-
- tions), or by special functions. The header files curs-
- es.h and term.h should be included (in this order) to get
- the definitions for these strings, numbers, and flags.
-
- 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 COL-
- UMNS exist, their values are used. If these environ-
- ment variables do not exist and the program is running
- in a window, the current window size is used. Other-
- wise, 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 ex-
- iting [see curs_kernel(3x)].
+
+ These low-level routines must be called by programs that have to deal
+ directly with the terminfo database to handle certain terminal capabil-
+ ities, such as programming function keys. For all other functionality,
+ curses routines are more suitable and their use is recommended.
+
+
+
+ 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)].
+
+ Applications can use the terminal capabilities either directly (via
+ header definitions), or by special functions. The header files curs-
+ es.h and term.h should be included (in this order) to get the defini-
+ tions for these strings, numbers, and flags.
+
+ 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
@@ -130,139 +140,163 @@
Programs which execute shell subprocesses should
- o call reset_shell_mode and output exit_ca_mode before
- the shell is called and
+ 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.
- 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:
- 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 er-
- rret. A return value of OK combined with status of 1 in
- errret is normal. If ERR is returned, examine errret:
+ term is the terminal type, a character string. If term is null, the
+ environment variable TERM is used.
- 1 means that the terminal is hardcopy, cannot be used
- for curses applications.
+ filedes
+ is the file descriptor used for all output.
- setupterm determines if the entry is a hardcopy type
- by checking the hc (hardcopy) capability.
+ errret
+ points to an optional location where an error status can be re-
+ turned 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 sta-
+ tus of 1 in errret is normal.
- 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.
+ If ERR is returned, examine errret:
- setupterm determines if the entry is a generic type
- by checking the gn (generic) capability.
+ 1 means that the terminal is hardcopy, cannot be used for
+ curses applications.
- -1 means that the terminfo database could not be found.
+ setupterm determines if the entry is a hardcopy type by
+ checking the hc (hardcopy) capability.
- If errret is null, setupterm prints an error message upon
- finding an error and exits. Thus, the simplest call is:
+ 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((char*)0,1,(int*)0);,
+ setupterm determines if the entry is a generic type by
+ checking the gn (generic) capability.
- which uses all the defaults and sends the output to std-
- out.
+ -1 means that the terminfo database could not be found.
+
+ If errret is null, setupterm prints an error message upon find-
+ ing 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 setterm routine was replaced by setupterm. The call:
setupterm(term,1,(int*)0)
- provides the same functionality as setterm(term). The
- setterm routine is provided for BSD compatibility, and is
- not recommended for new programs.
-
- TheTerminalState
- 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 ap-
- plications.
-
- 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 allo-
- cates 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.
-
- 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 re-
- fer 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.
-
- FormattingOutput
- The tparm routine instantiates the string str with parame-
- ters pi. A pointer is returned to the result of str with
- the parameters applied.
-
- tiparm is a newer form of tparm which uses <stdarg.h>
- rather than a fixed-parameter list. Its numeric parame-
- ters are integers (int) rather than longs.
-
- OutputFunctions
- 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 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.,
- one of type attr_t for the attributes and one of short for
- the color_pair number. The vid_attr and vid_puts routines
- are designed to use the attribute constants with the WA_
- prefix. The opts argument is reserved for future use.
- Currently, applications must provide a null pointer for
- that argument.
-
- The mvcur routine provides low-level cursor motion. It
- takes effect immediately (rather than at the next re-
- fresh).
-
- TerminalCapabilityFunctions
- The tigetflag, tigetnum and tigetstr routines return the
- value of the capability corresponding to the terminfocap-
- name 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).
+ provides the same functionality as setterm(term). The setterm routine
+ is provided for BSD compatibility, and is not recommended for new pro-
+ grams.
+
+
+
+ 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 termi-
+ nal's capabilities in memory. If it is called for different terminal
+ types, setupterm allocates new storage for each set of terminal capa-
+ bilities.
+
+ 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.
+
+ 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, refer-
+ ences to any of the terminfo boolean, numeric, and string variables
+ thereafter may refer to invalid memory locations until another se-
+ tupterm 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 exam-
+ ple, 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 inter-
+ face:
+
+ 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 capa-
+ bilities require no more than one or two parameters.
+
+ 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.
+
+
+
+ The tputs routine applies padding information to the string str and
+ outputs it:
+
+ 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 inter-
+ face.
+
+ oaffcnt is the number of lines affected, or 1 if not applicable.
+
+ oputc is a putchar-like routine to which the characters are passed,
+ one at a time.
+
+ The putp routine calls tputs(str,1,putchar). The output of putp al-
+ ways 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.
+
+ The vidattr routine is like the vidputs routine, except that it outputs
+ through putchar.
+
+ 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.,
+
+ oattrs of type attr_t for the attributes and
+
+ 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.
+
+ X/Open Curses reserves the opts argument for future use, saying that
+ applications must provide a null pointer for that argument. As an ex-
+ tension, this implementation allows opts to be used as a pointer to
+ int, which overrides the pair (short) argument.
+
+ 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 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.
@@ -270,163 +304,278 @@
-1 if capname is not a boolean capability, or
- 0 if it is canceled or absent from the terminal de-
- scription.
+ 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 de-
- scription.
+ -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 de-
- scription.
+ 0 if it is canceled or absent from the terminal description.
- TerminalCapabilityNames
- These null-terminated arrays contain the short terminfo
- names ("codes"), the termcap names, and the long terminfo
- names ("fnames") for each of the predefined terminfo vari-
- ables:
- char*boolnames[], *boolcodes[], *boolfnames[]
- char*numnames[], *numcodes[], *numfnames[]
+
+ These null-terminated arrays contain
- char*strnames[], *strcodes[], *strfnames[]
+ o the short terminfo names ("codes"),
+ o the termcap names ("names"), and
-
-
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.
+ 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[]
+
+
+
+ Routines that return an integer return ERR upon failure and OK (SVr4
+ only specifies "an integer value other than ERR") upon successful com-
+ pletion, 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 implementa-
- tion
+ 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 con-
+ ditions are documented above.
+
+ 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.
+
+
+
+ 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 char-
+ acters 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"):
+
+ 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 val-
+ ues (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 han-
+ dling functions such as vidattr (which used more than the two parame-
+ ters supported by tgoto).
+
+ SVr3 introduced the functions for switching between terminal descrip-
+ tions, e.g., set_curterm. The various global variables such as bool-
+ names were mentioned in the programming manual at this point.
+
+ 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 "obso-
+ lete" remained in use by the Unix vi editor.
+
+
+
+ X/Open notes that vidattr and vidputs may be macros.
+
+ The function setterm is not described by X/Open and must be considered
+ non-portable. All other functions are as described by X/Open.
- del_curterm
- returns an error if its terminal parameter is
- null.
- putp calls tputs, returning the same error-codes.
+
+ setupterm copies the terminal name to the array ttytype. This is not
+ part of X/Open Curses, but is assumed by some applications.
- restartterm
- returns an error if the associated call to se-
- tupterm returns an error.
+ Other implementions may not declare the capability name arrays. Some
+ provide them without declaring them. X/Open does not specify them.
- setupterm
- returns an error if it cannot allocate enough
- memory, or create the initial windows (stdscr,
- curscr, newscr). Other error conditions are
- documented above.
+ Extended terminal capability names, e.g., as defined by tic-x, are not
+ stored in the arrays described here.
- 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.
+
+ 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 ter-
+ minal 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.
-
-
PORTABILITY
- X/Open notes that vidattr and vidputs may be macros.
+ 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-lev-
+ el functions in ncurses use alternate versions of these functions using
+ the more reliable buffering scheme.
- The function setterm is not described by X/Open and must
- be considered non-portable. All other functions are as
- described by X/Open.
- setupterm copies the terminal name to the array ttytype.
- This is not part of X/Open Curses, but is assumed by some
- applications.
+
+ The X/Open Curses prototypes are based on the SVr4 curses header decla-
+ rations, which were defined at the same time the C language was first
+ standardized in the late 1980s.
- 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".
-
- osetupterm allows explicit use of the the windows con-
- sole driver by checking if $TERM is set to "#win32con"
- or an abbreviation of that string.
-
- 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 ad-
- dition to the limitation that the terminal was left in
- block-buffered mode on exit (like SystemV curses), it was
- problematic because ncurses did not allow a reliable way
- to cleanup on receiving SIGTSTP. The current version 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 using the more reliable buffering scheme.
-
- In System V Release 4, set_curterm has an int return type
- and returns 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).
-
- At least one implementation of X/Open Curses (Solaris) re-
- turns a value other than OK/ERR from tputs. That returns
- the length of the string, and does no error-checking.
-
- X/Open Curses prototypes tparm with a fixed number of pa-
- rameters, rather than a variable argument list. This im-
- plementation uses a variable argument list, but can be
- configured to use the fixed-parameter list. Portable ap-
- plications should provide 9 parameters after the format;
- zeroes are fine for this purpose.
-
- In response to comments by Thomas E. Dickey, X/Open Curses
- Issue 7 proposed the tiparm function in mid-2009.
-
- X/Open notes that after calling mvcur, the curses state
- may not match the actual terminal state, and that an ap-
- plication should touch and refresh the window before re-
- suming normal curses calls. Both ncurses and System V Re-
- lease 4 curses implement mvcur using the SCREEN data allo-
- cated in either initscr or newterm. So though it is docu-
- mented as a terminfo function, mvcur is really a curses
- function which is not well specified.
-
- 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.
-
- 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, e.g., as defined by
- tic-x, are not stored in the arrays described here.
+ 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.
+ 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.
-
-
SEE ALSO
- curses(3x), curs_initscr(3x), curs_kernel(3x), curs_term-
- cap(3x), curs_variables(3x), term_variables(3x), putc(3),
- terminfo(5)
+ 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 con-
+ figured 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.
+
+
+
+ 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".
+
+ 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 System V Release 4, set_curterm has an int return type and returns
+ 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).
+
+ 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.
+
+ X/Open notes that after calling mvcur, the curses state may not match
+ the actual terminal state, and that an application should touch and re-
+ fresh the window before resuming normal curses calls. Both ncurses and
+ System V Release 4 curses implement mvcur using the SCREEN data allo-
+ cated 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 states that the old location must be given for mvcur. This im-
+ plementation allows the caller to use -1's for the old ordinates. In
+ that case, the old location is unknown.
+
+
+