+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+
+</PRE><H3><a name="h3-Legacy-functions">Legacy functions</a></H3><PRE>
+ X/Open notes that <STRONG>vidattr</STRONG> and <STRONG>vidputs</STRONG> may be macros.
+
+ The function <STRONG>setterm</STRONG> is not described by X/Open and must be considered
+ non-portable. All other functions are as described by X/Open.
+
+
+</PRE><H3><a name="h3-Legacy-data">Legacy data</a></H3><PRE>
+ <STRONG>setupterm</STRONG> copies the terminal name to the array <STRONG>ttytype</STRONG>. This is not
+ part of X/Open Curses, but is assumed by some applications.
+
+ Other implementions may not declare the capability name arrays. Some
+ provide them without declaring them. X/Open does not specify them.
+
+ Extended terminal capability names, e.g., as defined by <STRONG>tic</STRONG> <STRONG>-x</STRONG>, are not
+ stored in the arrays described here.
+
+
+</PRE><H3><a name="h3-Output-buffering">Output buffering</a></H3><PRE>
+ Older versions of <STRONG>ncurses</STRONG> assumed that the file descriptor passed to
+ <STRONG>setupterm</STRONG> from <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG> uses buffered I/O, and would write to
+ the corresponding stream. In addition to the limitation that the ter-
+ minal was left in block-buffered mode on exit (like System V curses),
+ it was problematic because <STRONG>ncurses</STRONG> did not allow a reliable way to
+ cleanup on receiving SIGTSTP.
+
+ The current version (ncurses6) uses output buffers managed directly by
+ <STRONG>ncurses</STRONG>. Some of the low-level functions described in this manual page
+ write to the standard output. They are not signal-safe. The high-lev-
+ el functions in <STRONG>ncurses</STRONG> use alternate versions of these functions using
+ the more reliable buffering scheme.
+
+
+</PRE><H3><a name="h3-Function-prototypes">Function prototypes</a></H3><PRE>
+ The X/Open Curses prototypes are based on the SVr4 curses header decla-
+ rations, which were defined at the same time the C language was first
+ standardized in the late 1980s.
+
+ <STRONG>o</STRONG> X/Open Curses uses <STRONG>const</STRONG> less effectively than a later design
+ might, in some cases applying it needlessly to values are already
+ constant, and in most cases overlooking parameters which normally
+ would use <STRONG>const</STRONG>. Using constant parameters for functions which do
+ not use <STRONG>const</STRONG> may prevent the program from compiling. On the other
+ hand, <EM>writable</EM> <EM>strings</EM> are an obsolescent feature.
+
+ As an extension, this implementation can be configured to change
+ the function prototypes to use the <STRONG>const</STRONG> keyword. The ncurses ABI
+ 6 enables this feature by default.
+
+ <STRONG>o</STRONG> X/Open Curses prototypes <STRONG>tparm</STRONG> with a fixed number of parameters,
+ rather than a variable argument list.
+
+ This implementation uses a variable argument list, but can be con-
+ figured to use the fixed-parameter list. Portable applications
+ should provide 9 parameters after the format; zeroes are fine for
+ this purpose.
+
+ In response to review comments by Thomas E. Dickey, X/Open Curses
+ Issue 7 proposed the <STRONG>tiparm</STRONG> function in mid-2009.
+
+
+</PRE><H3><a name="h3-Special-TERM-treatment">Special TERM treatment</a></H3><PRE>
+ If configured to use the terminal-driver, e.g., for the MinGW port,
+
+ <STRONG>o</STRONG> <STRONG>setupterm</STRONG> interprets a missing/empty TERM variable as the special
+ value "unknown".
+
+ <STRONG>o</STRONG> <STRONG>setupterm</STRONG> allows explicit use of the the windows console driver by
+ checking if $TERM is set to "#win32con" or an abbreviation of that
+ string.
+
+
+</PRE><H3><a name="h3-Other-portability-issues">Other portability issues</a></H3><PRE>
+ In System V Release 4, <STRONG>set_curterm</STRONG> has an <STRONG>int</STRONG> return type and returns
+ <STRONG>OK</STRONG> or <STRONG>ERR</STRONG>. We have chosen to implement the X/Open Curses semantics.
+
+ In System V Release 4, the third argument of <STRONG>tputs</STRONG> has the type <STRONG>int</STRONG>
+ <STRONG>(*putc)(char)</STRONG>.
+
+ At least one implementation of X/Open Curses (Solaris) returns a value
+ other than <STRONG>OK</STRONG>/<STRONG>ERR</STRONG> from <STRONG>tputs</STRONG>. That returns the length of the string,
+ and does no error-checking.
+
+ X/Open notes that after calling <STRONG>mvcur</STRONG>, the curses state may not match
+ the actual terminal state, and that an application should touch and re-
+ fresh the window before resuming normal curses calls. Both <STRONG>ncurses</STRONG> and
+ System V Release 4 curses implement <STRONG>mvcur</STRONG> using the SCREEN data allo-
+ cated in either <STRONG>initscr</STRONG> or <STRONG>newterm</STRONG>. So though it is documented as a
+ terminfo function, <STRONG>mvcur</STRONG> is really a curses function which is not well
+ specified.
+
+ X/Open states that the old location must be given for <STRONG>mvcur</STRONG>. This im-
+ plementation allows the caller to use -1's for the old ordinates. In
+ that case, the old location is unknown.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_kernel.3x.html">curs_kernel(3x)</A></STRONG>, <STRONG><A HREF="curs_memleaks.3x.html">curs_memleaks(3x)</A></STRONG>,
+ <STRONG><A HREF="curs_termcap.3x.html">curs_termcap(3x)</A></STRONG>, <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG><A HREF="term_variables.3x.html">term_variables(3x)</A></STRONG>, <STRONG>putc(3)</STRONG>, <STRONG>ter-</STRONG>
+ <STRONG><A HREF="terminfo.5.html">minfo(5)</A></STRONG>