Provided by: ncurses-doc_6.2-0ubuntu2_all bug

NAME

       del_curterm, mvcur, putp, restartterm, set_curterm, setterm, setupterm, tigetflag,
       tigetnum, tigetstr, tiparm, tparm, tputs, vid_attr, vid_puts, vidattr, vidputs - curses
       interfaces to terminfo database

SYNOPSIS

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

       TERMINAL *cur_term;

       const char * const boolnames[];
       const char * const boolcodes[];
       const char * const boolfnames[];
       const char * const numnames[];
       const char * const numcodes[];
       const char * const numfnames[];
       const char * const strnames[];
       const char * const strcodes[];
       const char * const strfnames[];

       int setupterm(const char *term, int filedes, int *errret);
       int setterm(const char *term);
       TERMINAL *set_curterm(TERMINAL *nterm);
       int del_curterm(TERMINAL *oterm);
       int restartterm(const char *term, int filedes, int *errret);

       char *tparm(const char *str, ...);
       int tputs(const char *str, int affcnt, int (*putc)(int));
       int putp(const char *str);

       int vidputs(chtype attrs, int (*putc)(int));
       int vidattr(chtype attrs);
       int vid_puts(attr_t attrs, short pair, void *opts, int (*putc)(int));
       int vid_attr(attr_t attrs, short pair, void *opts);

       int mvcur(int oldrow, int oldcol, int newrow, int newcol);

       int tigetflag(const char *capname);
       int tigetnum(const char *capname);
       char *tigetstr(const char *capname);

       char *tiparm(const char *str, ...);

DESCRIPTION

       These  low-level  routines  must be called by programs that have to deal directly with the
       terminfo database to handle certain terminal capabilities, such  as  programming  function
       keys.   For  all  other  functionality, curses routines are more suitable and their use is
       recommended.

   Initialization
       Initially, setupterm should be  called.   The  high-level  curses  functions  initscr  and
       newterm  call  setupterm  to  initialize the low-level set of terminal-dependent variables
       [listed in terminfo(5)].

       Applications can use the terminal capabilities either directly (via  header  definitions),
       or by special functions.  The header files curses.h and term.h should be included (in this
       order) to get the definitions for these strings, numbers, and flags.

       The terminfo variables lines and columns are initialized by setupterm as follows:

       ·   If use_env(FALSE) has been called, values for lines and columns specified in  terminfo
           are used.

       ·   Otherwise,  if  the  environment  variables  LINES and COLUMNS exist, their values are
           used.  If these environment variables do not exist and the program  is  running  in  a
           window,  the  current window size is used.  Otherwise, if the environment variables do
           not exist, the values for lines and columns specified in  the  terminfo  database  are
           used.

       Parameterized  strings  should  be passed through tparm to instantiate them.  All terminfo
       strings (including the output of tparm) should  be  printed  with  tputs  or  putp.   Call
       reset_shell_mode to restore the tty modes before exiting [see kernel(3NCURSES)].

       Programs which use cursor addressing should

       ·   output enter_ca_mode upon startup and

       ·   output exit_ca_mode before exiting.

       Programs which execute shell subprocesses should

       ·   call reset_shell_mode and output exit_ca_mode before the shell is called and

       ·   output enter_ca_mode and call reset_prog_mode after returning from the shell.

       The   setupterm  routine  reads  in  the  terminfo  database,  initializing  the  terminfo
       structures, but does not set up the  output  virtualization  structures  used  by  curses.
       These are its parameters:

          term is  the  terminal  type,  a  character  string.   If term is null, the environment
               variable TERM is used.

          filedes
               is the file descriptor used for all output.

          errret
               points to an optional location where an  error  status  can  be  returned  to  the
               caller.   If  errret  is  not  null, then setupterm returns OK or ERR and stores a
               status value in the integer pointed to by errret.  A return value of  OK  combined
               with status of 1 in errret is normal.

               If ERR is returned, examine errret:

               1    means that the terminal is hardcopy, cannot be used for curses applications.

                    setupterm  determines  if  the  entry  is  a hardcopy type by checking the hc
                    (hardcopy) capability.

               0    means that the terminal could not be found, or that it  is  a  generic  type,
                    having too little information for curses applications to run.

                    setupterm  determines  if  the  entry  is  a  generic type by checking the gn
                    (generic) capability.

               -1   means that the terminfo database could not be found.

               If errret is null, setupterm prints an error message upon  finding  an  error  and
               exits.  Thus, the simplest call is:

                     setupterm((char *)0, 1, (int *)0);,

               which uses all the defaults and sends the output to stdout.

       The setterm routine was replaced by setupterm.  The call:

             setupterm(term, 1, (int *)0)

       provides the same functionality as setterm(term).  The setterm routine is provided for BSD
       compatibility, and is not recommended for new programs.

   The Terminal State
       The setupterm routine stores its information about the terminal in  a  TERMINAL  structure
       pointed  to  by the global variable cur_term.  If it detects an error, or decides that the
       terminal is unsuitable (hardcopy or generic), it discards this information, making it  not
       available to applications.

       If  setupterm  is  called  repeatedly  for  the  same  terminal  type,  it  will reuse the
       information.  It maintains only one copy of a given terminal's capabilities in memory.  If
       it is called for different terminal types, setupterm allocates new storage for each set of
       terminal capabilities.

       The set_curterm routine sets cur_term to nterm, and makes all  of  the  terminfo  boolean,
       numeric,  and  string  variables  use  the values from nterm.  It returns the old value of
       cur_term.

       The del_curterm routine frees the space pointed to by oterm and  makes  it  available  for
       further use.  If oterm is the same as cur_term, references to any of the terminfo boolean,
       numeric, and string variables thereafter may  refer  to  invalid  memory  locations  until
       another setupterm has been called.

       The  restartterm  routine  is  similar  to setupterm and initscr, except that it is called
       after restoring memory to a previous state (for example, when reloading a game saved as  a
       core  image  dump).  restartterm assumes that the windows and the input and output options
       are the same as when memory was saved,  but  the  terminal  type  and  baud  rate  may  be
       different.   Accordingly,  restartterm  saves various tty state bits, calls setupterm, and
       then restores the bits.

   Formatting Output
       The tparm routine instantiates the string str with parameters pi.  A pointer  is  returned
       to  the  result of str with the parameters applied.  Application developers should keep in
       mind these quirks of the interface:

       ·   Although tparm's actual parameters may be integers or strings, the  prototype  expects
           long (integer) values.

       ·   Aside  from the set_attributes (sgr) capability, most terminal capabilities require no
           more than one or two parameters.

       tiparm is a newer form of tparm which uses <stdarg.h> rather than a fixed-parameter  list.
       Its numeric parameters are integers (int) rather than longs.

   Output Functions
       The tputs routine applies padding information to the string str and outputs it:

       ·   The  str  parameter must be a terminfo string variable or the return value from tparm,
           tiparm, tgetstr, or tgoto.

           The tgetstr and tgoto functions are part of the termcap interface,  which  happens  to
           share this function name with the terminfo interface.

       ·   affcnt is the number of lines affected, or 1 if not applicable.

       ·   putc is a putchar-like routine to which the characters are passed, one at a time.

       The  putp routine calls tputs(str, 1, putchar).  The output of putp always goes to stdout,
       rather than the filedes specified in setupterm.

       The vidputs routine displays the string on the terminal in the video attribute mode attrs,
       which  is  any  combination of the attributes listed in ncurses(3NCURSES).  The characters
       are passed to the putchar-like routine putc.

       The vidattr routine is like the vidputs routine, except that it outputs through putchar.

       The vid_attr and vid_puts routines correspond to vidattr and vidputs, respectively.   They
       use a set of arguments for representing the video attributes plus color, i.e.,

       ·   attrs of type attr_t for the attributes and

       ·   pair of type short for the color-pair number.

       The  vid_attr  and  vid_puts routines are designed to use the attribute constants with the
       WA_ prefix.

       X/Open Curses reserves the opts argument for future use,  saying  that  applications  must
       provide  a  null  pointer  for that argument.  As an extension, this implementation allows
       opts to be used as a pointer to int, which overrides the pair (short) argument.

       The mvcur routine provides low-level cursor motion.  It takes effect  immediately  (rather
       than at the next refresh).

   Terminal Capability Functions
       The  tigetflag,  tigetnum  and  tigetstr  routines  return  the  value  of  the capability
       corresponding to the terminfo capname passed to them, such as xenl.  The capname for  each
       capability  is given in the table column entitled capname code in the capabilities section
       of terminfo(5).

       These routines return special values to denote errors.

       The tigetflag routine returns

       -1     if capname is not a boolean capability, or

       0      if it is canceled or absent from the terminal description.

       The tigetnum routine returns

       -2     if capname is not a numeric capability, or

       -1     if it is canceled or absent from the terminal description.

       The tigetstr routine returns

       (char *)-1
              if capname is not a string capability, or

       0      if it is canceled or absent from the terminal description.

   Terminal Capability Names
       These null-terminated arrays contain

       ·   the short terminfo names (“codes”),

       ·   the termcap names (“names”, and

       ·   the long terminfo names (“fnames”)

       for each of the predefined terminfo variables:

              const char *boolnames[], *boolcodes[], *boolfnames[]
              const char *numnames[], *numcodes[], *numfnames[]
              const char *strnames[], *strcodes[], *strfnames[]

RETURN VALUE

       Routines that return an integer return ERR upon failure and OK (SVr4  only  specifies  “an
       integer  value  other than ERR”) upon successful completion, unless otherwise noted in the
       preceding routine descriptions.

       Routines that return pointers always return NULL on error.

       X/Open defines no error conditions.  In this implementation

          del_curterm
               returns an error if its terminal parameter is null.

          putp calls tputs, returning the same error-codes.

          restartterm
               returns an error if the associated call to setupterm returns an error.

          setupterm
               returns an error if it cannot  allocate  enough  memory,  or  create  the  initial
               windows (stdscr, curscr, newscr).  Other error conditions are documented above.

          tputs
               returns  an error if the string parameter is null.  It does not detect I/O errors:
               X/Open states that tputs ignores the return value of the output function putc.

HISTORY

       SVr2 introduced the terminfo feature.  Its programming manual  mentioned  these  low-level
       functions:

       Function    Description
       ────────────────────────────────────────────────────────────
       fixterm     restore tty to “in curses” state
       gettmode    establish current tty modes
       mvcur       low level cursor motion
       putp        utility   function  that  uses  tputs  to  send
                   characters via putchar.
       resetterm   set tty modes to “out of curses” state
       resetty     reset tty flags to stored value
       saveterm    save current modes as “in curses” state
       savetty     store current tty flags
       setterm     establish terminal with given type
       setupterm   establish terminal with given type
       tparm       instantiate a string expression with parameters
       tputs       apply padding information to a string
       vidattr     like vidputs, but outputs through putchar
       vidputs     output a string to put terminal in a  specified
                   video attribute mode

       The  programming  manual  also  mentioned  functions  provided  for  termcap compatibility
       (commenting that they “may go away at a later date”):

       Function   Description
       ────────────────────────────────────────────────
       tgetent    look up termcap entry for given name
       tgetflag   get boolean entry for given id
       tgetnum    get numeric entry for given id
       tgetstr    get string entry for given id
       tgoto      apply parameters to given capability
       tputs      apply padding to capability, calling
                  a function to put characters

       Early terminfo programs obtained capability values from the TERMINAL structure initialized
       by setupterm.

       SVr3 extended terminfo by adding functions to retrieve capability values (like the termcap
       interface), and reusing tgoto and tputs:

       Function    Description
       ───────────────────────────────────────────
       tigetflag   get boolean entry for given id
       tigetnum    get numeric entry for given id
       tigetstr    get string entry for given id

       SVr3  also replaced several of the SVr2 terminfo functions which had no counterpart in the
       termcap interface, documenting them as obsolete:

       Function    Replaced by
       ─────────────────────────────
       crmode      cbreak

       fixterm     reset_prog_mode
       gettmode    N/A
       nocrmode    nocbreak
       resetterm   reset_shell_mode
       saveterm    def_prog_mode
       setterm     setupterm

       SVr3 kept the mvcur, vidattr and vidputs functions, along with putp, tparm and tputs.  The
       latter  were needed to support padding, and handling functions such as vidattr (which used
       more than the two parameters supported by tgoto).

       SVr3  introduced  the  functions  for  switching  between  terminal  descriptions,   e.g.,
       set_curterm.   The  various  global  variables  such  as  boolnames  were mentioned in the
       programming manual at this point.

       SVr4 added the vid_attr and vid_puts functions.

       There are other low-level functions declared in the curses header files on  Unix  systems,
       but  none were documented.  The functions marked “obsolete” remained in use by the Unix vi
       editor.

PORTABILITY

   Legacy functions
       X/Open notes that vidattr and vidputs may be macros.

       The function setterm is not described by X/Open and must be considered non-portable.   All
       other functions are as described by X/Open.

   Legacy data
       setupterm  copies  the  terminal  name  to  the array ttytype.  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 tic -x, are not stored in the
       arrays described here.

   Output buffering
       Older versions of ncurses assumed that  the  file  descriptor  passed  to  setupterm  from
       initscr  or  newterm  uses  buffered I/O, and would write to the corresponding stream.  In
       addition to the limitation that the terminal was left in block-buffered mode on exit (like
       System  V  curses),  it  was  problematic  because ncurses did not allow a reliable way to
       cleanup on receiving SIGTSTP.

       The current version (ncurses6) uses output buffers managed directly by ncurses.   Some  of
       the  low-level functions described in this manual page write to the standard output.  They
       are not signal-safe.  The high-level functions in ncurses use alternate versions of  these
       functions using the more reliable buffering scheme.

   Function prototypes
       The  X/Open Curses prototypes are based on the SVr4 curses header declarations, which were
       defined at the same time the C language was first standardized in the late 1980s.

       ·   X/Open Curses uses const 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 const.  Using constant  parameters  for  functions
           which  do  not  use  const may prevent the program from compiling.  On the other hand,
           writable strings are an obsolescent feature.

           As an extension,  this  implementation  can  be  configured  to  change  the  function
           prototypes  to  use  the  const  keyword.   The  ncurses ABI 6 enables this feature by
           default.

       ·   X/Open Curses prototypes tparm with a  fixed  number  of  parameters,  rather  than  a
           variable argument list.

           This  implementation  uses  a variable argument list, but can be configured 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
           tiparm function in mid-2009.

   Special TERM treatment
       If configured to use the terminal-driver, e.g., for the MinGW port,

       ·   setupterm interprets a missing/empty TERM variable as the special value “unknown”.

       ·   setupterm allows explicit use of the the windows console driver by checking  if  $TERM
           is set to “#win32con” or an abbreviation of that string.

   Other portability issues
       In  System V Release 4, set_curterm has an int return type and returns OK or ERR.  We have
       chosen to implement the X/Open Curses semantics.

       In System V Release 4, the third argument of tputs has the type int (*putc)(char).

       At least one implementation of X/Open Curses (Solaris) returns a value other  than  OK/ERR
       from tputs.  That returns the length of the string, and does no error-checking.

       X/Open  notes that after calling mvcur, the curses state may not match the actual terminal
       state, and that an application should touch and refresh the window before resuming  normal
       curses calls.  Both ncurses and System V Release 4 curses implement mvcur using the SCREEN
       data allocated in either initscr or newterm.  So though it is  documented  as  a  terminfo
       function, mvcur is really a curses function which is not well specified.

       X/Open  states  that the old location must be given for mvcur.  This implementation allows
       the caller to use -1's for the old ordinates.  In that case, the old location is unknown.

SEE ALSO

       ncurses(3NCURSES),      initscr(3NCURSES),      kernel(3NCURSES),       termcap(3NCURSES),
       curses_variables(3NCURSES), terminfo_variables(3NCURSES), putc(3), terminfo(5)

                                                                               terminfo(3NCURSES)