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 se-
- tupterm 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 values are used. If these en-
- vironment 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 speci-
- fied in the terminfo database are used.
+
+ Initially, setupterm should be called. The high-level
+ curses functions initscr and newterm call setupterm to
+ initialize the low-level set of terminal-dependent vari-
+ ables [listed in terminfo(5)].
+ Applications can use the terminal capabilities either di-
+ rectly (via header definitions), or by special functions.
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)]. Pro-
- grams which use cursor addressing should output en-
- ter_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 re-
- set_prog_mode after returning from the shell.
+ 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)].
+
+ 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, 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:
+ 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 all output.
+
+ errret
+ points to an optional location where an error sta-
+ tus 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.
+ 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.
+ setupterm determines if the entry is a hard-
+ copy type by checking the hc (hardcopy) capa-
+ bility.
- -1 means that the terminfo database could not be
- found.
+ 0 means that the terminal could not be found,
+ or that it is a generic type, having too lit-
+ tle information for curses applications to
+ run.
- If errret is null, setupterm prints an error message upon
- finding an error and exits. Thus, the simplest call is:
+ setupterm determines if the entry is a gener-
+ ic type by checking the gn (generic) capabil-
+ ity.
- setupterm((char*)0,1,(int*)0);,
+ -1 means that the terminfo database could not be
+ found.
- which uses all the defaults and sends the output to std-
- out.
+ If errret is null, setupterm prints an error mes-
+ sage upon finding an error and exits. Thus, the
+ simplest call is:
- The setterm routine is being replaced by setupterm. The
- call:
+ 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 included here for BSD compatibility,
- and is not recommended for new programs.
+ provides the same functionality as setterm(term). The
+ setterm routine is provided for BSD compatibility, and is
+ not recommended for new programs.
+
+
+
+ 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 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 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
@@ -171,30 +238,48 @@
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,
- calls setupterm, and then restores the bits.
+ 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 parame-
- ters pi. A pointer is returned to the result of str with
- the parameters applied.
+ ters 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.
- tiparm is a newer form of tparm which uses <stdarg.h>
- rather than a fixed-parameter list. Its numeric parame-
+ 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.
- 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 tputs routine applies padding information to the
+ string str and outputs it:
+
+ o The str must be a terminfo string variable or the re-
+ turn value from tparm, tgetstr, or tgoto.
+
+ 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 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
@@ -206,54 +291,79 @@
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-
+ 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 extension, this implementation al-
+ lows 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 re-
fresh).
- The tigetflag, tigetnum and tigetstr routines return the
+
+
+ The tigetflag, tigetnum and tigetstr routines return the
value of the capability corresponding to the terminfocap-
- name passed to them, such as xenl.
+ 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).
- 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.
+ These routines return special values to denote errors.
- The tigetnum routine returns the value -2 if capname is
- not a numeric capability, or -1 if it is canceled or ab-
- sent from the terminal description.
+ The tigetflag routine returns
- The tigetstr routine returns the value (char*)-1 if cap-
- name is not a string capability, or 0 if it is canceled or
- absent from the terminal description.
+ -1 if capname is not a boolean capability, or
- The capname for each capability is given in the table col-
- umn entitled capname code in the capabilities section of
- terminfo(5).
+ 0 if it is canceled or absent from the terminal de-
+ scription.
- char*boolnames[], *boolcodes[], *boolfnames[]
+ The tigetnum routine returns
- char*numnames[], *numcodes[], *numfnames[]
+ -2 if capname is not a numeric capability, or
- char*strnames[], *strcodes[], *strfnames[]
+ -1 if it is canceled or absent from the terminal de-
+ scription.
- These null-terminated arrays contain the capnames, the
- termcap codes, and the full C names, for each of the ter-
- minfo variables.
+ The tigetstr routine returns
+ (char*)-1
+ if capname is not a string capability, or
-
-
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
+ 0 if it is canceled or absent from the terminal de-
+ scription.
+
+
+
+ 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[], *boolf-
+ names[]
+ 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 completion, unless otherwise noted
in the preceding routine descriptions.
Routines that return pointers always return NULL on error.
@@ -261,103 +371,176 @@
X/Open defines no error conditions. In this implementa-
tion
- del_curterm
- returns an error if its terminal parameter is
- null.
+ del_curterm
+ returns an error if its terminal parameter is
+ null.
- putp calls tputs, returning the same error-codes.
+ putp calls tputs, returning the same error-codes.
- restartterm
- returns an error if the associated call to se-
- tupterm returns an error.
+ restartterm
+ returns an error if the associated call to se-
+ tupterm 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.
+ setupterm
+ returns an error if it cannot allocate enough mem-
+ ory, or create the initial windows (stdscr,
+ curscr, newscr). Other error conditions are docu-
+ mented 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.
+ 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 func-
+ tion putc.
-
-
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.
-
- Note that vidattr and vidputs may be macros.
+
+ X/Open notes that vidattr and vidputs may be macros.
-
-
PORTABILITY
- The function setterm is not described by X/Open and must
- be considered non-portable. All other functions are as
+ 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
+
+
+ setupterm copies the terminal name to the array ttytype.
+ This is not part of X/Open Curses, but is assumed by some
applications.
- In System V Release 4, set_curterm has an int return type
- and returns OK or ERR. We have chosen to implement the
+ 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.
+
+
+
+ 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 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 de-
+ scribed 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.
+
+
+
+ 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 over-
+ looking 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.
+
+ 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 af-
+ ter 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 con-
+ sole 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) re-
- turns a value other than OK/ERR from tputs. That returns
+ 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 tiparam 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-
+ 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
+ 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
+ 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.
- Extended terminal capability names, e.g., as defined by
- tic-x, are not stored in the arrays described in this
- section.
-
-