1resizeterm(3X)                                                  resizeterm(3X)
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NAME

6       is_term_resized,  resize_term,  resizeterm - change the curses terminal
7       size
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SYNOPSIS

10       #include <curses.h>
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12       bool is_term_resized(int lines, int columns);
13       int resize_term(int lines, int columns);
14       int resizeterm(int lines, int columns);
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DESCRIPTION

17       This is an extension to the curses library.  It provides callers with a
18       hook into the ncurses data to resize windows, primarily for use by pro‐
19       grams running in an X Window terminal (e.g., xterm).
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21   resizeterm
22       The function resizeterm resizes the standard and current windows to the
23       specified  dimensions,  and  adjusts other bookkeeping data used by the
24       ncurses library that record the window dimensions such as the LINES and
25       COLS variables.
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27   resize_term
28       Most  of the work is done by the inner function resize_term.  The outer
29       function resizeterm adds bookkeeping for the SIGWINCH handler, as  well
30       as repainting the soft-key area (see slk_touch(3X)).
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32       When  resizing  the windows, resize_term blank-fills the areas that are
33       extended.  The calling application should fill in these areas with  ap‐
34       propriate data.
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36       The  resize_term function attempts to resize all windows.  However, due
37       to the calling convention of pads, it is not possible to  resize  these
38       without additional interaction with the application.
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40       When  resizing  windows,  resize_term  recursively  adjusts subwindows,
41       keeping them within the updated parent window's limits.  If a top-level
42       window  happens  to extend to the screen's limits, then on resizing the
43       window, resize_term will keep the window extending to the corresponding
44       limit, regardless of whether the screen has shrunk or grown.
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46   is_term_resized
47       A support function is_term_resized is provided so that applications can
48       check if the resize_term function would modify the  window  structures.
49       It returns TRUE if the windows would be modified, and FALSE otherwise.
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RETURN VALUE

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

58       While these functions are intended to be used to support a signal  han‐
59       dler  (i.e., for SIGWINCH), care should be taken to avoid invoking them
60       in a context where malloc or realloc may have been  interrupted,  since
61       it uses those functions.
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63       If ncurses is configured to supply its own SIGWINCH handler,
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65       •   on receipt of a SIGWINCH, the handler sets a flag
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67       •   which is tested in wgetch(3X) and doupdate,
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69       •   in turn, calling the resizeterm function,
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71       •   which ungetch's a KEY_RESIZE which will be read on the next call to
72           wgetch.
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74           The KEY_RESIZE alerts an  application  that  the  screen  size  has
75           changed,  and  that it should repaint special features such as pads
76           that cannot be done automatically.
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78           Calling resizeterm or resize_term directly from a signal handler is
79           unsafe.   This indirect method is used to provide a safe way to re‐
80           size the ncurses data structures.
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82       If the environment variables LINES or COLUMNS are set,  this  overrides
83       the  library's  use of the window size obtained from the operating sys‐
84       tem.  Thus, even if a SIGWINCH is received, no screen size  change  may
85       be recorded.
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PORTABILITY

88       It is possible to resize the screen with SVr4 curses, by
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90       •   exiting curses with endwin(3X) and
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92       •   resuming using refresh(3X).
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94       Doing that clears the screen and is visually distracting.
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96       This  extension  of ncurses was introduced in mid-1995.  It was adopted
97       in NetBSD curses (2001) and PDCurses (2003).
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SEE ALSO

100       curs_getch(3X), curs_variables(3X), wresize(3X).
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AUTHOR

103       Thomas Dickey (from an equivalent function  written  in  1988  for  BSD
104       curses).
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108                                                                resizeterm(3X)
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