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curs_terminfo 3x

curs_terminfo(3x)                                            curs_terminfo(3x)




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 capabil-
       ities, 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 curs-
       es.h and term.h should be included (in this order) to get  the  defini-
       tions for these strings, numbers, and flags.

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

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

       o   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 curs_kernel(3x)].

       Programs which use cursor addressing should

       o   output enter_ca_mode upon startup and

       o   output exit_ca_mode before exiting.

       Programs which execute shell subprocesses should

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

       o   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 re-
               turned  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 sta-
               tus 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 find-
               ing 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 pro-
       grams.


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 termi-
       nal's capabilities in memory.  If it is called for  different  terminal
       types,  setupterm  allocates new storage for each set of terminal capa-
       bilities.

       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, refer-
       ences to any of the terminfo boolean,  numeric,  and  string  variables
       thereafter  may  refer  to  invalid  memory locations until another se-
       tupterm 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 exam-
       ple, 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  inter-
       face:

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

       o   Aside from the set_attributes (sgr) capability, most terminal capa-
           bilities 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:

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

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

       o   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  al-
       ways 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  curses(3x).   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.,

       o   attrs of type attr_t for the attributes and

       o   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 ex-
       tension, 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

       o   the short terminfo names ("codes"),

       o   the termcap names ("names", and

       o   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  com-
       pletion, 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 con-
               ditions 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.


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  ter-
       minal  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-lev-
       el 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 decla-
       rations, which were defined at the same time the C language  was  first
       standardized in the late 1980s.

       o   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.

       o   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 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 tiparm function in mid-2009.


Special TERM treatment

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

       o   setupterm  interprets  a missing/empty TERM variable as the special
           value "unknown".

       o   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 re-
       fresh the window before resuming normal curses calls.  Both ncurses and
       System  V  Release 4 curses implement mvcur using the SCREEN data allo-
       cated 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  im-
       plementation  allows  the caller to use -1's for the old ordinates.  In
       that case, the old location is unknown.


SEE ALSO

       curses(3x),   curs_initscr(3x),   curs_kernel(3x),    curs_termcap(3x),
       curs_variables(3x), term_variables(3x), putc(3), terminfo(5)



                                                             curs_terminfo(3x)