NCURSES API

Index

Initialization Functions

  • initscr() - Start curses mode.

  • raw() and cbreak() - Normally the terminal driver buffers the characters a user types until a new line or carriage return is encountered. But most programs require that the characters be available as soon as the user types them. The above two functions are used to disable line buffering. The difference between these two functions is in the way control characters like suspend (CTRL-Z), interrupt and quit (CTRL-C) are passed to the program. In the raw() mode these characters are directly passed to the program without generating a signal. In the cbreak() mode these control characters are interpreted as any other character by the terminal driver.

  • echo() and noecho() - if noecho() is used key press will not echoed in the screen. other do the oposite.

  • keypad(stdscr, TRUE) - To get special inputs like F1, F2, Arrow keys etc.

Input / Output Functions

For each input/output functions there are four types of function.

  • Normal : printw(string) - print in the current position of the cursor in the standard screen(stdscr).
  • w less mv type: mvprintw(y, x, string) - move cursor to x, y then print in that position in the stdscr.
  • w type : wprintw(window, string) - print string in the current cursor position of the specified window.
  • w ed mv type : mvwprintw(window, y, x, string) - move to x, y and then print string in the specified window.

Output Functions

  • printw(string) - print string.
  • addch(ch, attributes) - print single character.
  • addstr(string) - print string.

NB: Each function has corresponding mv, w, mvw functions.

Input Functions

  • ch = getch() - to get a character from keyboard.
  • scanw() - scanf() like function.
  • getstr(str) - to get a string.

NB: Each function has corresponding mv, w, mvw functions.

Attributes

Attributes are used to set different text properties. Like Bold, Underlined, Italic etc.

  • attron(attribute1 | attrubute2 | ...) - To set some attribute on.
  • attroff(attr1 | attr2 | ...) - to set some attribute off.
  • attrset(attr1 | attr2 | ...) - Remove any prevoius attributes and set specified attributes.

Here is a list of some attributes:

Attribute Effect
A_NORMAL Normal Output
A_STANDOUT Best highlighting mode of the terminal
A_UNDERLINE Underlined
A_REVERSE Reverse video
A_BLINK Blinking
A_DIM Half bright
A_BOLD Extra bright or bold
A_PROTECT Protected mode
A_INVIS Invisible or blank mode
A_ALTCHARSET Alternate character set
A_CHARTEXT Bit-mask to extract a character
COLOR_PAIR(n) Color-pair number n

NB: There is also corresponding w functions like wattron() which work on specific window.

  • chgat(nChar, attribute, color_pair_token, null) - This function set an attribute on texts without changing cursor position. nChar is the number of char on which attribute will be set. Negative nChar means end of the line. color_pair_token is for color pair. last is always null.

  • mvchgat(y, x, nChar, attribute, color_pair_token, null) - chgat() from x, y position.

Managing Windows

  • WINDOW *newwin(height, width, starty, startx) - To create a new window. It takes height and width of the window as argument. Also takes x, y position of the window. Returns a WINDOW pointer.

  • delwin(WINDOW *win) - To remove a window.

  • box(window, vchar, hchar) - vchar & hchar is ther char which will be used to draw boxes vertical and horizontal lines.

  • wborder(window, ls, rs, ts, bt, tl, tr, bl, br) - 2 - 8 arguments are character for drawing ls(left side), rs(right side) of the box.