terminfo(3)

NAME
del_curterm, mvcur, putp, restartterm, set_curterm, setterm, setupterm, tigetflag, tigetnum, tigetstr, tparm, tputs, vid_attr, vid_puts, vidattr, vidputs - curses interfaces to terminfo database

SYNOPSIS
#include <curses.h>
#include <term.h>

int setupterm(char *term, int fildes, int *errret);
int setterm(char *term);
TERMINAL *set_curterm(TERMINAL *nterm);
int del_curterm(TERMINAL *oterm);
int restartterm(char *term, int fildes, int *errret);
char *tparm(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)(char));
int vid_attr(attr_t attrs, short pair, void *opts);
int mvcur(int oldrow, int oldcol, int newrow, int newcol);
int tigetflag(char *capname);
int tigetnum(char *capname);
char *tigetstr(char *capname);

DESCRIPTION
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.

Initially, setupterm should be called. Note that setupterm 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 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.

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(3)]. Programs which use cursor addressing should output enter_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 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. The terminal 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 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.

    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.

    -1  means that the terminfo database could not be found.

If errret is null, setupterm prints an error message 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 is being 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.

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 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.

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 memory 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.

The tparm routine instantiates the string str with parameters pi. A pointer is returned to the result of str with the parameters applied.

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(3). 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 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 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.

The tigetnum routine returns the value -2 if capname is not a numeric capability, or -1 if it is canceled or absent from the terminal description.

The tigetstr routine returns the value (char *)-1 if capname is not a string capability, or 0 if it is canceled or absent from the terminal description.

The capname for each capability is given in the table column entitled capname code in the capabilities section of terminfo(5).

    char *boolnames[], *boolcodes[], *boolfnames[]

    char *numnames[], *numcodes[], *numfnames[]

    char *strnames[], *strcodes[], *strfnames[]

These null-terminated arrays contain the capnames, the termcap codes, and the full C names, for each of the terminfo variables.

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.

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.

    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.

NOTES
The setupterm routine should be used in place of setterm. It may be useful when you want to test for terminal capabilities without committing to the allocation of storage involved in initscr.

Note 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 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.

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 Curses prototypes tparm with a fixed number of parameters, rather than a variable argument list. This implementation uses a variable argument list. Portable applications should provide 9 parameters after the format; zeroes are fine for this purpose.

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.

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.

SEE ALSO
curses(3), curs_initscr(3), curs_kernel(3), putc(3), termcap(3), terminfo(5)