WINDOW *newpad(int nlines, int ncols);
WINDOW *subpad(WINDOW *orig, int nlines, int ncols,
int begin_y, int begin_x);
int prefresh(WINDOW *pad, int pminrow, int pmincol,
int sminrow, int smincol, int smaxrow, int smaxcol);
int pnoutrefresh(WINDOW *pad, int pminrow, int pmincol,
int sminrow, int smincol, int smaxrow, int smaxcol);
int pechochar(WINDOW *pad, chtype ch);
int pecho_wchar(WINDOW *pad, const cchar_t *wch);
The subpad routine creates and returns a pointer to a subwindow within a pad with the given number of lines, nlines, and columns, ncols. Unlike subwin, which uses screen coordinates, the window is at position (begin_x, begin_y) on the pad. The window is made in the middle of the window orig, so that changes made to one window affect both windows. During the use of this routine, it will often be necessary to call touchwin or touchline on orig before calling prefresh.
The prefresh and pnoutrefresh routines are analogous to wrefresh and wnoutrefresh except that they relate to pads instead of windows. The additional parameters are needed to indicate what part of the pad and screen are involved. The pminrow and pmincol parameters specify the upper left-hand corner of the rectangle to be displayed in the pad. The sminrow, smincol, smaxrow, and smaxcol parameters specify the edges of the rectangle to be displayed on the screen. The lower right-hand corner of the rectangle to be displayed in the pad is calculated from the screen coordinates, since the rectangles must be the same size. Both rectangles must be entirely contained within their respective structures. Negative values of pminrow, pmincol, sminrow, or smincol are treated as if they were zero.
The pechochar routine is functionally equivalent to a call to addch followed by a call to refresh, a call to waddch followed by a call to wrefresh, or a call to waddch followed by a call to prefresh. The knowledge that only a single character is being output is taken into consideration and, for non-control characters, a considerable performance gain might be seen by using these routines instead of their equivalents. In the case of pechochar, the last location of the pad on the screen is reused for the arguments to prefresh.
The pecho_wchar function is the analogous wide-character form of pechochar. It outputs one character to a pad and immediately refreshes the pad. It does this by a call to wadd_wch followed by a call to prefresh.
Routines that return pointers return NULL on error, and set errno to ENOMEM.
X/Open does not define any error conditions. In this implementation