Provided by: ncurses-doc_5.9+20140118-1ubuntu1_all bug

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  parameters  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 terminal description in the area referenced by this pointer.  However,
              ncurses stores its terminal descriptions 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 description is marked with the generic  capability,  or  if  the  terminal
              description has cursor-addressing.

   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 termcap applications assume me  (terminfo  sgr0)  does  not  reset  the  alternate
       character set.  This implementation 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   applications'   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 developers.  The original BSD  4.2  termcap  library  (and  historical  relics
       thereof)  did  not  require  a  trailing 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)