The unctrl routine returns a character string which is a printable representation of the character c, ignoring attributes. Control characters are displayed in the ^X notation. Printing characters are displayed as is. The corresponding wunctrl returns a printable representation of a wide-character.
The keyname routine returns a character string corresponding to the key c. Control characters are displayed in the ^X notation. Values above 128 are either meta characters, shown in the M-X notation, or the names of function keys, or "UNKNOWN STRING". The corresponding key_name returns a character string corresponding to the wide-character value w. The two functions do not return the same set of strings; the latter returns "UNKNOWN STRING" where the former would display a meta character.
The filter routine, if used, must be called before initscr or newterm are called. The effect is that, during those calls, LINES is set to 1; the capabilities clear, cup, cud, cud1, cuu1, cuu, vpa are disabled; and the home string is set to the value of cr.
The use_env routine, if used, is called before initscr or newterm are called. When called with FALSE as an argument, the values of lines and columns specified in the terminfo database will be used, even if environment variables LINES and COLUMNS (used by default) are set, or if curses is running in a window (in which case default behavior would be to use the window size if LINES and COLUMNS are not set).
The putwin routine writes all data associated with window win into the file to which filep points. This information can be later retrieved using the getwin function.
The getwin routine reads window related data stored in the file by putwin. The routine then creates and initializes a new window using that data. It returns a pointer to the new window.
The delay_output routine inserts an ms millisecond pause in output. This routine should not be used extensively because padding characters are used rather than a CPU pause.
The flushinp routine throws away any typeahead that has been typed by the user and has not yet been read by the program.
Except for flushinp, routines that return an integer return ERR upon failure and OK (SVr4 specifies only "an integer value other than ERR") upon successful completion.
flushinp always returns OK.
Routines that return pointers return NULL on error.
The XSI Curses standard, Issue 4 describes these functions. It states that unctrl and wunctrl will return a null pointer if unsuccessful, but does not define any error conditions.
The SVr4 documentation describes the action of filter only in the vaguest terms. The description here is adapted from the XSI Curses standard (which erroneously fails to describe the disabling of cuu).
curses(3), curs_initscr(3), curs_scr_dump(3).