tail head cat sleep
QR code linking to this page

Manual Pages  — resizeterm

NAME

is_term_resized, resize_term, resizeterm - change the curses terminal size

CONTENTS

SYNOPSIS

#include <curses.h>

bool is_term_resized(int lines, int columns);
int resize_term(int lines, int columns);
int resizeterm(int lines, int columns);

DESCRIPTION

This is an extension to the curses library. It provides callers with a hook into the ncurses data to resize windows, primarily for use by programs running in an X Window terminal (e.g., xterm). The function resizeterm resizes the standard and current windows to the specified dimensions, and adjusts other bookkeeping data used by the ncurses library that record the window dimensions such as the LINES and COLS variables.

Most of the work is done by the inner function resize_term. The outer function resizeterm adds bookkeeping for the SIGWINCH handler. When resizing the windows, resize_term blank-fills the areas that are extended. The calling application should fill in these areas with appropriate data. The resize_term function attempts to resize all windows. However, due to the calling convention of pads, it is not possible to resize these without additional interaction with the application.

A support function is_term_resized is provided so that applications can check if the resize_term function would modify the window structures. It returns TRUE if the windows would be modified, and FALSE otherwise.

RETURN VALUE

Except as noted, these functions return the integer ERR upon failure and OK on success. They will fail if either of the dimensions are less than or equal to zero, or if an error occurs while (re)allocating memory for the windows.

NOTES

While these functions are intended to be used to support a signal handler (i.e., for SIGWINCH), care should be taken to avoid invoking them in a context where malloc or realloc may have been interrupted, since it uses those functions.

If ncurses is configured to supply its own SIGWINCH handler, the resizeterm function ungetch's a KEY_RESIZE which will be read on the next call to getch. This is used to alert an application that the screen size has changed, and that it should repaint special features such as pads that cannot be done automatically.

If the environment variables LINES or COLUMNS are set, this overrides the library's use of the window size obtained from the operating system. Thus, even if a SIGWINCH is received, no screen size change may be recorded.

SEE ALSO

curs_getch(3), curs_variables(3), wresize(3).

AUTHOR

Thomas Dickey (from an equivalent function written in 1988 for BSD curses).

resizeterm (3X)

tail head cat sleep
QR code linking to this page


Please direct any comments about this manual page service to Ben Bullock. Privacy policy.

As soon as we started programming, we found to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs.
— Maurice Wilkes