curs_terminfo 3x

curs_terminfo(3x)                                            curs_terminfo(3x)


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


       #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);
       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, ...);


       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.

       None of these functions use  (or  are  aware  of)  multibyte  character
       strings such as UTF-8:

       o   capability names use the POSIX portable character set

       o   capability  string  values  have  no  associated encoding; they are
           strings of 8-bit characters.


       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

       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.

               is the file descriptor used for all output.

               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 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

       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-

       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-

       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.

       o   Padding  information  is  ignored  by  tparm;  it is interpreted by

       o   The capability string is  null-terminated.   Use  "\200"  where  an
           ASCII NUL is needed in the output.

       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 (i.e., by interpreting
       marker embedded in the terminfo capability such as  "$<5>"  as  5  mil-
       liseconds) to the string str and outputs it:

       o   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 inter-

       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

       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).

       While putp and mvcur are low-level functions which do not use the high-
       level curses state, they are declared in <curses.h> because SystemV did
       this (see HISTORY).

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[]


       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

               returns an error if its terminal parameter is null.

          putp calls tputs, returning the same error-codes.

               returns an error if the associated call to setupterm returns an

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

               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.

Compatibility macros

       This  implementation  provides a few macros for compatibility with sys-
       tems  before  SVr4  (see  HISTORY).   Those  include  crmode,  fixterm,
       gettmode, nocrmode, resetterm, saveterm, and setterm.

       In  SVr4,  those  are  found in <curses.h>, but except for setterm, are
       likewise macros.  The one function, setterm, is mentioned in the manual
       page.   The  manual page notes that the setterm routine was replaced by
       setupterm, stating that the call:

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

       provides the same functionality as setterm(term), and is not recommend-
       ed  for  new programs.  This implementation provides each of those sym-
       bols as macros for BSD compatibility,


       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 char-
                   acters 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  val-
       ues (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 han-
       dling functions such as vidattr (which used more than the  two  parame-
       ters supported by tgoto).

       SVr3  introduced  the functions for switching between terminal descrip-
       tions, e.g., set_curterm.  The various global variables such  as  bool-
       names 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 "obso-
       lete" remained in use by the Unix vi editor.


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

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

       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

       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.


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