# curs_slk 3x

    curs_slk(3x)                                               curs_slk(3x)

## NAME

           slk_init, slk_set, 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_number, void* opts);
           attr_t slk_attr(void);
           int slk_color(short color_pair_number);

## 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  most  common
           for  todays  PC  like  enduser  devices.  Please note that
           ncurses simulates this mode by taking over up to two lines
           at  the  bottom  of  the screen, it doesn't 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.  Setting fmt to 0
           indicates a 3-2-3 arrangement of the labels, 1 indicates a
           4-4 arrangement and 2 indicates the PC like 4-4-4 mode. If
           fmt is set to 3, it 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 requires labnum to be a label  number,
           from 1 to 8 (resp. 12); label must be the string to be put
           on the label, up  to  eight  (resp.  five)  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-justi-
           fied, respectively, within the label.

           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_slk(3x)