+</PRE><H3><a name="h3-unctrl">unctrl</a></H3><PRE>
+ The <STRONG>unctrl</STRONG> routine returns a character string which is a printable
+ representation of the character <EM>ch</EM>:
+
+ <STRONG>o</STRONG> Printable characters are displayed as themselves, e.g., a one-
+ character string containing the key.
+
+ <STRONG>o</STRONG> Control characters are displayed in the <STRONG>^</STRONG><EM>X</EM> notation.
+
+ <STRONG>o</STRONG> Printing characters are displayed as is.
+
+ <STRONG>o</STRONG> DEL (character 127) is displayed as <STRONG>^?</STRONG>.
+
+ <STRONG>o</STRONG> Values above 128 are either meta characters (if the screen has not
+ been initialized, or if <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> has been called with a <STRONG>TRUE</STRONG>
+ parameter), shown in the <STRONG>M-</STRONG><EM>X</EM> notation, or are displayed as
+ themselves. In the latter case, the values may not be printable;
+ this follows the X/Open specification.
+
+ The corresponding <STRONG>wunctrl</STRONG> returns a printable representation of a
+ complex character <EM>wch</EM>.
+
+ In both <STRONG>unctrl</STRONG> and <STRONG>wunctrl</STRONG> the attributes and color associated with the
+ character parameter are ignored.
+
+
+</PRE><H3><a name="h3-keyname_key_name">keyname, key_name</a></H3><PRE>
+ The <STRONG>keyname</STRONG> routine returns a character string corresponding to the key
+ <EM>c</EM>. Key codes are different from character codes.
+
+ <STRONG>o</STRONG> Key codes below 256 are characters. They are displayed using
+ <STRONG>unctrl</STRONG>.
+
+ <STRONG>o</STRONG> Values above 256 may be the codes for function keys. The function
+ key name is displayed.
+
+ <STRONG>o</STRONG> Otherwise (if there is no corresponding name and the key is not a
+ character) the function returns null, to denote an error. X/Open
+ also lists an "UNKNOWN KEY" return value, which some
+ implementations return rather than null.
+
+ The corresponding <STRONG>key_name</STRONG> returns a multibyte character string
+ corresponding to the wide-character value <EM>w</EM>. The two functions
+ (<STRONG>keyname</STRONG> and <STRONG>key_name</STRONG>) do not return the same set of strings:
+
+ <STRONG>o</STRONG> <STRONG>keyname</STRONG> returns null where <STRONG>key_name</STRONG> would display a meta character.
+
+ <STRONG>o</STRONG> <STRONG>key_name</STRONG> does not return the name of a function key.
+
+
+</PRE><H3><a name="h3-filter_nofilter">filter, nofilter</a></H3><PRE>
+ The <STRONG>filter</STRONG> routine, if used, must be called before <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG>
+ are called. Calling <STRONG>filter</STRONG> causes these changes in initialization:
+
+ <STRONG>o</STRONG> <STRONG>LINES</STRONG> is set to 1;
+
+ <STRONG>o</STRONG> the capabilities <STRONG>clear</STRONG>, <STRONG>cud1</STRONG>, <STRONG>cud</STRONG>, <STRONG>cup</STRONG>, <STRONG>cuu1</STRONG>, <STRONG>cuu</STRONG>, <STRONG>vpa</STRONG> are
+ disabled;
+
+ <STRONG>o</STRONG> the capability <STRONG>ed</STRONG> is disabled if <STRONG>bce</STRONG> is set;
+
+ <STRONG>o</STRONG> and the <STRONG>home</STRONG> string is set to the value of <STRONG>cr</STRONG>.
+
+ The <STRONG>nofilter</STRONG> routine cancels the effect of a preceding <STRONG>filter</STRONG> call.
+ That allows the caller to initialize a screen on a different device,
+ using a different value of <STRONG>$TERM</STRONG>. The limitation arises because the
+ <STRONG>filter</STRONG> routine modifies the in-memory copy of the terminal information.
+
+
+</PRE><H3><a name="h3-use_env">use_env</a></H3><PRE>
+ 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 <EM>ncurses</EM> treats environment variables when determining
+ the screen size.
+
+ <STRONG>o</STRONG> Normally <EM>ncurses</EM> 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 <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> parameter), <EM>ncurses</EM>
+ examines the <EM>LINES</EM> or <EM>COLUMNS</EM> environment variables, using a value
+ in those to override the results from the operating system or
+ terminal database.
+
+ <EM>curses</EM> also updates the screen size in response to <STRONG>SIGWINCH</STRONG>, unless
+ overridden by the <EM>LINES</EM> or <EM>COLUMNS</EM> environment variables,
+
+
+</PRE><H3><a name="h3-use_tioctl">use_tioctl</a></H3><PRE>
+ 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, <EM>ncurses</EM> modifies the
+ last step in its computation of screen size as follows:
+
+ <STRONG>o</STRONG> checks if the <EM>LINES</EM> and <EM>COLUMNS</EM> environment variables are set to a
+ number greater than zero.
+
+ <STRONG>o</STRONG> for each, <EM>ncurses</EM> updates the corresponding environment variable
+ with the value that it has obtained via operating system call or
+ from the terminal database.
+
+ <STRONG>o</STRONG> <EM>ncurses</EM> re-fetches the value of the environment variables 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 follows.
+
+ <STRONG>use_env</STRONG> <STRONG>use_tioctl</STRONG> <STRONG>Summary</STRONG>
+ -----------------------------------------------------------------
+ <STRONG>TRUE</STRONG> <STRONG>FALSE</STRONG> This is the default behavior. <EM>ncurses</EM>
+ uses operating system calls unless
+ overridden by <EM>LINES</EM> or <EM>COLUMNS</EM>
+ environment variables; default.
+ <STRONG>TRUE</STRONG> <STRONG>TRUE</STRONG> <EM>ncurses</EM> updates <EM>LINES</EM> and <EM>COLUMNS</EM> based
+ on operating system calls.
+ <STRONG>FALSE</STRONG> <STRONG>TRUE</STRONG> <EM>ncurses</EM> ignores <EM>LINES</EM> and <EM>COLUMNS</EM>, using
+ operating system calls to obtain size.
+
+
+</PRE><H3><a name="h3-putwin_getwin">putwin, getwin</a></H3><PRE>
+ The <STRONG>putwin</STRONG> routine writes all data associated with window (or pad) <EM>win</EM>
+ into the file to which <EM>filep</EM> points. This information can be later
+ retrieved using the <STRONG>getwin</STRONG> function.
+
+ The <STRONG>getwin</STRONG> routine reads window related data stored in the file by
+ <STRONG>putwin</STRONG>. The routine then creates and initializes a new window using
+ that data. It returns a pointer to the new window. There are a few
+ caveats:
+
+ <STRONG>o</STRONG> the data written is a copy of the <EM>WINDOW</EM> structure, and its
+ associated character cells. The format differs between the wide-
+ character (<EM>ncursesw</EM>) and non-wide (<EM>ncurses</EM>) libraries. You can
+ transfer data between the two, however.
+
+ <STRONG>o</STRONG> the retrieved window is always created as a top-level window (or
+ pad), rather than a subwindow.
+
+ <STRONG>o</STRONG> the window's character cells contain the color pair <EM>value</EM>, but not
+ the actual color <EM>numbers</EM>. If cells in the retrieved window use
+ color pairs which have not been created in the application using
+ <STRONG>init_pair</STRONG>, they will not be colored when the window is refreshed.
+
+
+</PRE><H3><a name="h3-delay_output">delay_output</a></H3><PRE>
+ The <STRONG>delay_output</STRONG> routine inserts an <EM>ms</EM> millisecond pause in output.
+ Employ this function judiciously when terminal output uses padding,
+ because <EM>ncurses</EM> transmits null characters (consuming CPU and I/O
+ resources) instead of sleeping and requesting resumption from the
+ operating system. Padding is used unless:
+
+ <STRONG>o</STRONG> the terminal description has <STRONG>npc</STRONG> (<STRONG>no_pad_char</STRONG>) capability, or
+
+ <STRONG>o</STRONG> the environment variable <STRONG>NCURSES_NO_PADDING</STRONG> is set.
+
+ If padding is not in use, <EM>ncurses</EM> uses <STRONG>napms</STRONG> to perform the delay. If
+ the value of <EM>ms</EM> exceeds 30,000 (thirty seconds), it is capped at that
+ value.
+
+
+</PRE><H3><a name="h3-flushinp">flushinp</a></H3><PRE>
+ The <STRONG>flushinp</STRONG> routine throws away any typeahead that has been typed by
+ the user and has not yet been read by the program.
+
+
+</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ Except for <STRONG>flushinp</STRONG>, routines that return an integer return <STRONG>ERR</STRONG> upon
+ failure and <STRONG>OK</STRONG> (SVr4 specifies only "an integer value other than <STRONG>ERR</STRONG>")
+ upon successful completion.