NAME

       PC, UP, BC, ospeed, tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs - direct curses interface to the
       terminfo capability database

SYNOPSIS

       #include <curses.h>
       #include <term.h>

       extern char PC;
       extern char * UP;
       extern char * BC;
       extern short ospeed;

       int tgetent(char *bp, const char *name);
       int tgetflag(char *id);
       int tgetnum(char *id);
       char *tgetstr(char *id, char **area);
       char *tgoto(const char *cap, int col, int row);
       int tputs(const char *str, int affcnt, int (*putc)(int));

DESCRIPTION

       These routines are included as a conversion aid for programs that use the termcap library.  Their parame‐
       ters are the same and the routines are emulated using the terminfo database.  Thus, they can only be used
       to query the capabilities of entries for which a terminfo entry has been compiled.

   INITIALIZATION
       The tgetent routine loads the entry for name.  It returns:

          1  on success,

          0  if  there  is no such entry (or that it is a generic type, having too little information for curses
             applications to run), and

          -1 if the terminfo database could not be found.

       This differs from the termcap library in two ways:

          •   The emulation ignores the buffer pointer bp.  The termcap library would store a copy of the termi‐
              nal description in the area referenced by this pointer.  However, ncurses stores its terminal  de‐
              scriptions in compiled binary form, which is not the same thing.

          •   There  is  a  difference  in return codes.  The termcap library does not check if the terminal de‐
              scription is marked with the generic capability, or if the  terminal  description  has  cursor-ad‐
              dressing.

   CAPABILITY VALUES
       The tgetflag routine gets the boolean entry for id, or zero if it is not available.

       The tgetnum routine gets the numeric entry for id, or -1 if it is not available.

       The tgetstr routine returns the string entry for id, or zero if it is not available.  Use tputs to output
       the returned string.  The return value will also be copied to the buffer pointed to by area, and the area
       value will be updated to point past the null ending this value.

       Only  the  first  two  characters  of  the  id parameter of tgetflag, tgetnum and tgetstr are compared in
       lookups.

   FORMATTING CAPABILITIES
       The tgoto routine instantiates the parameters into the given capability.  The output from this routine is
       to be passed to tputs.

       The tputs routine is described on the terminfo(3NCURSES) manual page.  It can  retrieve  capabilities  by
       either termcap or terminfo name.

   GLOBAL VARIABLES
       The  variables  PC, UP and BC are set by tgetent to the terminfo entry's data for pad_char, cursor_up and
       backspace_if_not_bs, respectively.  UP is not used by ncurses.  PC is used in the tdelay_output function.
       BC is used in the tgoto emulation.  The variable ospeed is set by ncurses in a system-specific coding  to
       reflect the terminal speed.

RETURN VALUE

       Except  where explicitly noted, routines that return an integer return ERR upon failure and OK (SVr4 only
       specifies "an integer value other than ERR") upon successful completion.

       Routines that return pointers return NULL on error.

BUGS

       If you call tgetstr to fetch ca or any other parameterized string, be aware that it will be  returned  in
       terminfo notation, not the older and not-quite-compatible termcap notation.  This will not cause problems
       if all you do with it is call tgoto or tparm, which both expand terminfo-style strings as terminfo.  (The
       tgoto  function,  if  configured to support termcap, will check if the string is indeed terminfo-style by
       looking for "%p" parameters or "$<..>" delays, and invoke a termcap-style parser if the string  does  not
       appear to be terminfo).

       Because  terminfo  conventions  for  representing  padding  in string capabilities differ from termcap's,
       tputs("50"); will put out a literal "50" rather than busy-waiting for 50 milliseconds.  Cope with it.

       Note that termcap has nothing analogous to terminfo's sgr string.  One consequence of this is that  term‐
       cap  applications assume me (terminfo sgr0) does not reset the alternate character set.  This implementa‐
       tion checks for, and modifies the data shown to the termcap interface to accommodate termcap's limitation
       in this respect.

PORTABILITY

       The XSI Curses standard, Issue 4 describes these functions.  However, they are marked TO BE WITHDRAWN and
       may be removed in future versions.

       Neither the XSI Curses standard nor the SVr4 man pages documented the return values of tgetent correctly,
       though all three were in fact returned ever since SVr1.  In particular, an omission  in  the  XSI  Curses
       documentation  has  been  misinterpreted  to mean that tgetent returns OK or ERR.  Because the purpose of
       these functions is to provide compatibility with the termcap library, that is a defect in XCurses,  Issue
       4, Version 2 rather than in ncurses.

       External  variables  are provided for support of certain termcap applications.  However, termcap applica‐
       tions' use of those variables is poorly documented, e.g., not distinguishing between  input  and  output.
       In particular, some applications are reported to declare and/or modify ospeed.

       The  comment that only the first two characters of the id parameter are used escapes many application de‐
       velopers.  The original BSD 4.2 termcap library (and historical relics thereof) did not require a  trail‐
       ing  null  NUL  on  the parameter name passed to tgetstr, tgetnum and tgetflag.  Some applications assume
       that the termcap interface does not require the trailing NUL for the parameter name.  Taking into account
       these issues:

       •   As a special case, tgetflag matched against a single-character identifier provided that  was  at  the
           end  of the terminal description.  You should not rely upon this behavior in portable programs.  This
           implementation disallows matches against single-character capability names.

       •   This implementation disallows matches by the termcap  interface  against  extended  capability  names
           which are longer than two characters.

SEE ALSO

       ncurses(3NCURSES), terminfo(5), terminfo_variables(3NCURSES), putc(3).

       http://invisible-island.net/ncurses/tctest.html

                                                                                               termcap(3NCURSES)