trusty (3) is_term_resized.3ncurses.gz

NAME

       is_term_resized, resize_term, resizeterm - change the curses terminal size

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

       getch(3NCURSES), curses_variables(3NCURSES), wresize(3NCURSES).

AUTHOR

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

                                                                                            resizeterm(3NCURSES)