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- * @Id: curs_initscr.3x,v 1.59 2023/12/17 23:56:04 tom Exp @
+ * @Id: curs_initscr.3x,v 1.60 2023/12/23 16:27:25 tom Exp @
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-<H1 class="no-header">curs_initscr 3x 2023-12-17 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_initscr 3x 2023-12-23 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>
use <STRONG>newterm</STRONG>.
The routine <STRONG>newterm</STRONG> should be called once for each terminal. It
- returns a variable of type <STRONG>SCREEN</STRONG> <STRONG>*</STRONG> which should be saved as a
+ returns a variable of type <EM>SCREEN</EM> <EM>*</EM> which should be saved as a
reference to that terminal. <STRONG>newterm</STRONG>'s arguments are
<STRONG>o</STRONG> the <EM>type</EM> of the terminal to be used in place of <STRONG>$TERM</STRONG>,
If the <EM>type</EM> parameter is <STRONG>NULL</STRONG>, <STRONG>$TERM</STRONG> will be used.
The file descriptor of the output stream is passed to <STRONG><A HREF="curs_terminfo.3x.html">setupterm(3x)</A></STRONG>,
- which returns a pointer to a <STRONG>TERMINAL</STRONG> structure. <STRONG>newterm</STRONG>'s return
- value holds a pointer to the <STRONG>TERMINAL</STRONG> structure.
+ which returns a pointer to a <EM>TERMINAL</EM> structure. <STRONG>newterm</STRONG>'s return
+ value holds a pointer to the <EM>TERMINAL</EM> structure.
</PRE><H3><a name="h3-endwin">endwin</a></H3><PRE>
The <STRONG>set_term</STRONG> routine is used to switch between different terminals.
The screen reference <EM>new</EM> becomes the new current terminal. The
previous terminal is returned by the routine. This is the only routine
- which manipulates <STRONG>SCREEN</STRONG> pointers; all other routines affect only the
+ which manipulates <EM>SCREEN</EM> pointers; all other routines affect only the
current terminal.
</PRE><H3><a name="h3-delscreen">delscreen</a></H3><PRE>
- The <STRONG>delscreen</STRONG> routine frees storage associated with the <STRONG>SCREEN</STRONG> data
+ The <STRONG>delscreen</STRONG> routine frees storage associated with the <EM>SCREEN</EM> data
structure. The <STRONG>endwin</STRONG> routine does not do this, so <STRONG>delscreen</STRONG> should be
- called after <STRONG>endwin</STRONG> if a particular <STRONG>SCREEN</STRONG> is no longer needed.
+ called after <STRONG>endwin</STRONG> if a particular <EM>SCREEN</EM> is no longer needed.
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
redundant to check the return value of <STRONG>initscr</STRONG> in XSI Curses.
Calling <STRONG>endwin</STRONG> does not dispose of the memory allocated in <STRONG>initscr</STRONG> or
- <STRONG>newterm</STRONG>. Deleting a <STRONG>SCREEN</STRONG> provides a way to do this:
+ <STRONG>newterm</STRONG>. Deleting a <EM>SCREEN</EM> provides a way to do this:
- <STRONG>o</STRONG> X/Open Curses does not say what happens to <STRONG>WINDOW</STRONG>s when <STRONG>delscreen</STRONG>
- "frees storage associated with the <STRONG>SCREEN</STRONG>" nor does the SVr4
+ <STRONG>o</STRONG> X/Open Curses does not say what happens to <EM>WINDOW</EM>s when <STRONG>delscreen</STRONG>
+ "frees storage associated with the <EM>SCREEN</EM>" nor does the SVr4
documentation help, adding that it should be called after <STRONG>endwin</STRONG> if
- a <STRONG>SCREEN</STRONG> is no longer needed.
+ a <EM>SCREEN</EM> is no longer needed.
- <STRONG>o</STRONG> However, <STRONG>WINDOW</STRONG>s are implicitly associated with a <STRONG>SCREEN</STRONG>. so that
+ <STRONG>o</STRONG> However, <EM>WINDOW</EM>s are implicitly associated with a <EM>SCREEN</EM>. so that
it is reasonable to expect <STRONG>delscreen</STRONG> to deal with these.
- <STRONG>o</STRONG> SVr4 curses deletes the standard <STRONG>WINDOW</STRONG> structures <STRONG>stdscr</STRONG> and
+ <STRONG>o</STRONG> SVr4 curses deletes the standard <EM>WINDOW</EM> structures <STRONG>stdscr</STRONG> and
<STRONG>curscr</STRONG> as well as a work area <STRONG>newscr</STRONG>. SVr4 curses ignores other
windows.
windows when <STRONG>delscreen</STRONG> is called.
<STRONG>o</STRONG> NetBSD copied this feature of <EM>ncurses</EM> in 2001. PDCurses follows
- the SVr4 model, deleting only the standard <STRONG>WINDOW</STRONG> structures.
+ the SVr4 model, deleting only the standard <EM>WINDOW</EM> structures.
</PRE><H3><a name="h3-High-level-versus-Low-level">High-level versus Low-level</a></H3><PRE>
Different implementations may disagree regarding the level of some
- functions. For example, <STRONG>SCREEN</STRONG> (returned by <STRONG>newterm</STRONG>) and <STRONG>TERMINAL</STRONG>
+ functions. For example, <EM>SCREEN</EM> (returned by <STRONG>newterm</STRONG>) and <EM>TERMINAL</EM>
(returned by <STRONG><A HREF="curs_terminfo.3x.html">setupterm(3x)</A></STRONG>) hold file descriptors for the output
stream. If an application switches screens using <STRONG>set_term</STRONG>, or switches
terminals using <STRONG><A HREF="curs_terminfo.3x.html">set_curterm(3x)</A></STRONG>, applications which use the output file
For example
- <STRONG>o</STRONG> NetBSD's <STRONG><A HREF="curs_termattrs.3x.html">baudrate(3x)</A></STRONG> function uses the descriptor in <STRONG>TERMINAL</STRONG>.
- <EM>ncurses</EM> and SVr4 use the descriptor in <STRONG>SCREEN</STRONG>.
+ <STRONG>o</STRONG> NetBSD's <STRONG><A HREF="curs_termattrs.3x.html">baudrate(3x)</A></STRONG> function uses the descriptor in <EM>TERMINAL</EM>.
+ <EM>ncurses</EM> and SVr4 use the descriptor in <EM>SCREEN</EM>.
- <STRONG>o</STRONG> NetBSD and <EM>ncurses</EM> use the descriptor in <STRONG>TERMINAL</STRONG> for terminal I/O
+ <STRONG>o</STRONG> NetBSD and <EM>ncurses</EM> use the descriptor in <EM>TERMINAL</EM> for terminal I/O
modes, e.g., <STRONG><A HREF="curs_kernel.3x.html">def_shell_mode(3x)</A></STRONG>, <STRONG><A HREF="curs_kernel.3x.html">def_prog_mode(3x)</A></STRONG>. SVr4 curses
- uses the descriptor in <STRONG>SCREEN</STRONG>.
+ uses the descriptor in <EM>SCREEN</EM>.
<STRONG>Unset</STRONG> <EM>TERM</EM> <STRONG>Variable</STRONG>
If the <EM>TERM</EM> variable is missing or empty, <STRONG>initscr</STRONG> uses the value
The handler <EM>attempts</EM> to cleanup the screen on exit. Although it
<EM>usually</EM> works as expected, there are limitations:
- <STRONG>o</STRONG> Walking the <STRONG>SCREEN</STRONG> list is unsafe, since all list management
+ <STRONG>o</STRONG> Walking the <EM>SCREEN</EM> list is unsafe, since all list management
is done without any signal blocking.
<STRONG>o</STRONG> On systems which have <STRONG>REENTRANT</STRONG> turned on, <STRONG>set_term</STRONG> uses
functions which could deadlock or misbehave in other ways.
- <STRONG>o</STRONG> <STRONG>endwin</STRONG> calls other functions, many of which use stdio or other
- library functions which are clearly unsafe.
+ <STRONG>o</STRONG> <STRONG>endwin</STRONG> calls other functions, many of which use <STRONG>stdio(3)</STRONG> or
+ other library functions which are clearly unsafe.
<STRONG>SIGTERM</STRONG>
This uses the same handler as <STRONG>SIGINT</STRONG>, with the same limitations.
-ncurses 6.4 2023-12-
17 <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>
+ncurses 6.4 2023-12-
23 <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>
</PRE>
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