curs_terminfo(3x) curs_terminfo(3x)
del_curterm, mvcur, putp, restartterm, set_curterm, setterm, setupterm,
tigetflag, tigetnum, tigetstr, tiparm, tparm, tputs, vid_attr,
vid_puts, vidattr, vidputs - curses interfaces to terminfo database
#include <curses.h>
#include <term.h>
TERMINAL *cur_term;
const char * const boolnames[];
const char * const boolcodes[];
const char * const boolfnames[];
const char * const numnames[];
const char * const numcodes[];
const char * const numfnames[];
const char * const strnames[];
const char * const strcodes[];
const char * const strfnames[];
int setupterm(const char *term, int filedes, int *errret);
int setterm(const char *term);
TERMINAL *set_curterm(TERMINAL *nterm);
int del_curterm(TERMINAL *oterm);
int restartterm(const char *term, int filedes, int *errret);
char *tparm(const char *str, ...);
int tputs(const char *str, int affcnt, int (*putc)(int));
int putp(const char *str);
int vidputs(chtype attrs, int (*putc)(int));
int vidattr(chtype attrs);
int vid_puts(attr_t attrs, short pair, void *opts, int (*putc)(int));
int vid_attr(attr_t attrs, short pair, void *opts);
int mvcur(int oldrow, int oldcol, int newrow, int newcol);
int tigetflag(const char *capname);
int tigetnum(const char *capname);
char *tigetstr(const char *capname);
char *tiparm(const char *str, ...);
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
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 all output.
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.
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) capability.
-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 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 must be a terminfo string variable or the return value from
tparm, tgetstr, or tgoto.
o affcnt is the number of lines affected, or 1 if not applicable.
o putc 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.,
o attrs of type attr_t for the attributes and
o pair 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 terminfo capname 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:
const char *boolnames[], *boolcodes[], *boolfnames[]
const char *numnames[], *numcodes[], *numfnames[]
const char *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 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.
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.
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, 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 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.
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 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.
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 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,
o setupterm interprets a missing/empty TERM variable as the special
value "unknown".
o setupterm 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.
curses(3x), curs_initscr(3x), curs_kernel(3x), curs_termcap(3x),
curs_variables(3x), term_variables(3x), putc(3), terminfo(5)
curs_terminfo(3x)