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 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. 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.
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. 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.
setupterm determines if the entry is a hard-
copy type by checking the hc (hardcopy) capa-
bility.
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.
setupterm determines if the entry is a gener-
ic type by checking the gn (generic) capabil-
ity.
-1 means that the terminfo database could not be
found.
If errret is null, setupterm prints an error mes-
sage upon finding an error and exits. Thus, the
simplest call is:
setupterm((char *)0, 1, (int *)0);,
which uses all the defaults and sends the output
to stdout.
The 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.
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.
The tparm routine instantiates the string str with parame-
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-
ters 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 re-
turn 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 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.
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 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
value of the capability corresponding to the terminfo cap-
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).
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 de-
scription.
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.
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.
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[], *boolf-
names[]
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 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 implementa-
tion
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 se-
tupterm returns an error.
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 func-
tion 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 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, writable strings are an obsolescent
feature.
As an extension, this implementation can be configured
to change the function prototypes to use the const
keyword. The ncurses ABI 6 enables this feature by
default.
o X/Open Curses prototypes tparm with a fixed number of
parameters, rather than a variable argument list.
This implementation uses a variable argument list, but
can be configured to use the fixed-parameter list.
Portable applications should provide 9 parameters 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,
o setupterm interprets a missing/empty TERM variable as
the special value "unknown".
o setupterm 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
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 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.
curses(3x), curs_initscr(3x), curs_kernel(3x), curs_term-
cap(3x), curs_variables(3x), term_variables(3x), putc(3),
terminfo(5)
curs_terminfo(3x)