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</PRE>
<H2>NAME</H2><PRE>
<STRONG>delay_output</STRONG>, <STRONG>filter</STRONG>, <STRONG>flushinp</STRONG>, <STRONG>getwin</STRONG>, <STRONG>key_name</STRONG>, <STRONG>keyname</STRONG>,
- <STRONG>nofilter</STRONG>, <STRONG>putwin</STRONG>, <STRONG>unctrl</STRONG>, <STRONG>use_env</STRONG>, <STRONG>wunctrl</STRONG> - miscellaneous
- <STRONG>curses</STRONG> utility routines
+ <STRONG>nofilter</STRONG>, <STRONG>putwin</STRONG>, <STRONG>unctrl</STRONG>, <STRONG>use_env</STRONG>, <STRONG>use_tioctl</STRONG>, <STRONG>wunctrl</STRONG> -
+ miscellaneous <STRONG>curses</STRONG> utility routines
</PRE>
<STRONG>void</STRONG> <STRONG>filter(void);</STRONG>
<STRONG>void</STRONG> <STRONG>nofilter(void);</STRONG>
<STRONG>void</STRONG> <STRONG>use_env(bool</STRONG> <STRONG>f);</STRONG>
+ <STRONG>void</STRONG> <STRONG>use_tioctl(bool</STRONG> <STRONG>f);</STRONG>
<STRONG>int</STRONG> <STRONG>putwin(WINDOW</STRONG> <STRONG>*win,</STRONG> <STRONG>FILE</STRONG> <STRONG>*filep);</STRONG>
<STRONG>WINDOW</STRONG> <STRONG>*getwin(FILE</STRONG> <STRONG>*filep);</STRONG>
<STRONG>int</STRONG> <STRONG>delay_output(int</STRONG> <STRONG>ms);</STRONG>
<STRONG>$TERM</STRONG>. The limitation arises because the <STRONG>filter</STRONG> routine
modifies the in-memory copy of the terminal information.
- The <STRONG>use_env</STRONG> routine, if used, is called before <STRONG>initscr</STRONG> or
- <STRONG>newterm</STRONG> are called. When called with <STRONG>FALSE</STRONG> as an argu-
- ment, the values of <STRONG>lines</STRONG> and <STRONG>columns</STRONG> specified in the
- <EM>terminfo</EM> database will be used, even if environment vari-
- ables <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> (used by default) are set, or if
- <STRONG>curses</STRONG> is running in a window (in which case default be-
- havior would be to use the window size if <STRONG>LINES</STRONG> and
- <STRONG>COLUMNS</STRONG> are not set). Note that setting <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG>
- overrides the corresponding size which may be obtained
- from the operating system.
+ The <STRONG>use_env</STRONG> routine, if used, should be called before
+ <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG> are called (because those compute the
+ screen size). It modifies the way <STRONG>ncurses</STRONG> treats environ-
+ ment variables when determining the screen size.
+
+ <STRONG>o</STRONG> Normally ncurses looks first at the terminal database
+ for the screen size.
+
+ If <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> for parameter, it
+ stops here unless If <STRONG>use_tioctl</STRONG> was also called with
+ <STRONG>TRUE</STRONG> for parameter.
+
+ <STRONG>o</STRONG> Then it asks for the screen size via operating system
+ calls. If successful, it overrides the values from
+ the terminal database.
+
+ <STRONG>o</STRONG> Finally (unless <STRONG>use_env</STRONG> was called with <STRONG>FALSE</STRONG> parame-
+ ter), ncurses examines the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG> environ-
+ ment variables, using a value in those to override the
+ results from the operating system or terminal data-
+ base.
+
+ Ncurses also updates the screen size in response to
+ SIGWINCH, unless overridden by the <STRONG>LINES</STRONG> or <STRONG>COLUMNS</STRONG>
+ environment variables,
+
+ The <STRONG>use_tioctl</STRONG> routine, if used, should be called before
+ <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG> are called (because those compute the
+ screen size). After <STRONG>use_tioctl</STRONG> is called with <STRONG>TRUE</STRONG> as an
+ argument, ncurses modifies the last step in its computa-
+ tion of screen size as follows:
+
+ <STRONG>o</STRONG> checks if the <STRONG>LINES</STRONG> and <STRONG>COLUMNS</STRONG> environment variables
+ are set to a number greater than zero.
+
+ <STRONG>o</STRONG> for each, ncurses updates the corresponding environ-
+ ment variable with the value that it has obtained via
+ operating system call or from the terminal database.
+
+ <STRONG>o</STRONG> ncurses re-fetches the value of the environment vari-
+ ables so that it is still the environment variables
+ which set the screen size.
+
+ The <STRONG>use_env</STRONG> and <STRONG>use_tioctl</STRONG> routines combine as summarized
+ here:
+
+ <EM>use</EM><STRONG>_</STRONG><EM>env</EM> <EM>use</EM><STRONG>_</STRONG><EM>tioctl</EM> <EM>Summary</EM>
+ ----------------------------------------------------------------
+ TRUE FALSE This is the default behavior. ncurses
+ uses operating system calls unless over-
+ ridden by $LINES or $COLUMNS environment
+ variables.
+ TRUE TRUE ncurses updates $LINES and $COLUMNS
+ based on operating system calls.
+
+ FALSE TRUE ncurses ignores $LINES and $COLUMNS, us-
+ es operating system calls to obtain
+ size.
+ FALSE FALSE ncurses relies on the terminal database
+ to determine size.
The <STRONG>putwin</STRONG> routine writes all data associated with window
<EM>win</EM> into the file to which <EM>filep</EM> points. This information
loaded when the terminal description is read by the li-
brary.
- The <STRONG>nofilter</STRONG> routine is specific to ncurses. It was not
- supported on Version 7, BSD or System V implementations.
- It is recommended that any code depending on ncurses ex-
- tensions be conditioned using NCURSES_VERSION.
+ The <STRONG>nofilter</STRONG> and <STRONG>use_tioctl</STRONG> routines are specific to
+ ncurses. They were not supported on Version 7, BSD or
+ System V implementations. It is recommended that any code
+ depending on ncurses extensions be conditioned using
+ NCURSES_VERSION.
</PRE>
<H2>SEE ALSO</H2><PRE>
<STRONG><A HREF="legacy_coding.3x.html">legacy_coding(3x)</A></STRONG>, <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG>curs_ker-</STRONG>
- <STRONG><A HREF="curs_kernel.3x.html">nel(3x)</A></STRONG>, <STRONG><A HREF="curs_scr_dump.3x.html">curs_scr_dump(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG>lega-</STRONG>
+ <STRONG><A HREF="curs_kernel.3x.html">nel(3x)</A></STRONG>, <STRONG><A HREF="curs_scr_dump.3x.html">curs_scr_dump(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG>lega-</STRONG>
<STRONG><A HREF="legacy_coding.3x.html">cy_coding(3x)</A></STRONG>.
projects / ncurses.git / blobdiff