# curs_slk 3x

    curs_slk(3x)                                               curs_slk(3x)

## NAME

           slk_init, slk_set, slk_wset, slk_refresh, slk_noutrefresh,
           slk_label, slk_clear, slk_restore, slk_touch, slk_attron,
           slk_attrset, slk_attroff, slk_attr_on, slk_attr_set,
           slk_attr_off, slk_attr, slk_color - curses soft label
           routines

## SYNOPSIS

           #include <curses.h>

           int slk_init(int fmt);
           int slk_set(int labnum, const char *label, int fmt);
           int slk_refresh(void);
           int slk_noutrefresh(void);
           char *slk_label(int labnum);
           int slk_clear(void);
           int slk_restore(void);
           int slk_touch(void);
           int slk_attron(const chtype attrs);
           int slk_attroff(const chtype attrs);
           int slk_attrset(const chtype attrs);
           int slk_attr_on(attr_t attrs, void* opts);
           int slk_attr_off(const attr_t attrs, void * opts);
           int  slk_attr_set(const  attr_t  attrs,  short color_pair,
           void* opts);
           attr_t slk_attr(void);
           int slk_color(short color_pair);
           int slk_wset(int labnum, const wchar_t *label, int fmt);

## DESCRIPTION

           The slk* functions manipulate the set of soft function-key
           labels  that exist on many terminals.  For those terminals
           that do not have soft labels, curses takes over the bottom
           line  of stdscr, reducing the size of stdscr and the vari-
           able LINES.  curses standardizes on eight labels of up  to
           eight  characters  each.  In addition to this, the ncurses
           implementation supports a mode where it simulates  12  la-
           bels  of  up  to five characters each.  This is useful for
           today's PC-like enduser devices.  ncurses  simulates  this
           mode  by  taking over up to two lines at the bottom of the
           screen; it does not try to use any  hardware  support  for
           this mode.

           The  slk_init  routine  must  be  called before initscr or
           newterm is called.  If initscr eventually uses a line from
           stdscr to emulate the soft labels, then fmt determines how
           the labels are arranged on the screen:

                  0  indicates a 3-2-3 arrangement of the labels.

                  1  indicates a 4-4 arrangement

                  2  indicates the PC-like 4-4-4 mode.

                  3  is again the PC-like 4-4-4 mode, but in addition
                     an  index line is generated, helping the user to
                     identify the key numbers easily.

           The slk_set routine (and  the  slk_wset  routine  for  the
           wide-character library) has three parameters:

                  labnum
                       is  the  label number, from 1 to 8 (12 for fmt
                       in slk_init is 2 or 3);

                  label
                       is be the string to put on the  label,  up  to
                       eight  (five  for  fmt  in slk_init is 2 or 3)
                       characters in length.  A null string or a null
                       pointer sets up a blank label.

                  fmt  is  either  0, 1, or 2, indicating whether the
                       label is to be  left-justified,  centered,  or
                       right-justified,  respectively, within the la-
                       bel.

           The slk_refresh and slk_noutrefresh routines correspond to
           the wrefresh and wnoutrefresh routines.

           The  slk_label routine returns the current label for label
           number labnum, with leading and trailing blanks stripped.

           The slk_clear routine clears  the  soft  labels  from  the
           screen.

           The  slk_restore  routine  restores the soft labels to the
           screen after a slk_clear has been performed.

           The slk_touch routine forces all the  soft  labels  to  be
           output the next time a slk_noutrefresh is performed.

           The slk_attron, slk_attrset, slk_attroff and slk_attr rou-
           tines correspond to attron, attrset, attroff and attr_get.
           They  have  an effect only if soft labels are simulated on
           the bottom line of the screen.  The default highlight  for
           soft keys is A_STANDOUT (as in System V curses, which does
           not document this fact).

           The slk_color routine corresponds to color_set.  It has an
           effect  only  if  soft  labels are simulated on the bottom
           line of the screen.

## RETURN VALUE

           These routines return ERR upon failure and OK (SVr4 speci-
           fies only "an integer value other than ERR") upon success-
           ful completion.

           X/Open defines no error conditions.  In  this  implementa-
           tion

                  slk_attr
                       returns the attribute used for the soft keys.

                  slk_attroff, slk_attron, slk_clear,
                  slk_noutrefresh, slk_refresh, slk_touch
                       return an error if the terminal or  the  soft-
                       keys were not initialized.

                  slk_attrset
                       returns  an error if the terminal or the soft-
                       keys were not initialized.

                  slk_attr_set
                       returns an error if the terminal or the  soft-
                       keys  were  not initialized, or the color pair
                       is outside the range 0..COLOR_PAIRS-1, or opts
                       is not null.

                  slk_color
                       returns  an error if the terminal or the soft-
                       keys were not initialized, or the  color  pair
                       is outside the range 0..COLOR_PAIRS-1.

                  slk_init
                       returns  an  error  if the format parameter is
                       outside the range 0..3.

                  slk_label
                       returns NULL on error.

                  slk_set
                       returns an error if the terminal or the  soft-
                       keys  were  not initialized, or the labnum pa-
                       rameter is outside the range of label  counts,
                       or  if  the  format  parameter  is outside the
                       range 0..2, or if memory for the labels cannot
                       be allocated.

## NOTES

           Most applications would use slk_noutrefresh because a wre-
           fresh is likely to follow soon.

## PORTABILITY

           The XSI Curses standard, Issue 4,  describes  these  func-
           tions.   It changes the argument type of the attribute-ma-
           nipulation functions slk_attron, slk_attroff,  slk_attrset
           to be attr_t, and adds const qualifiers.  The format codes
           2 and 3 for slk_init() and the function slk_attr are  spe-
           cific to ncurses.

## SEE ALSO

           curses(3x),   curs_attr(3x),   curs_initscr(3x),  curs_re-
           fresh(3x), curs_variables(3x).

                                                               curs_slk(3x)