/* fscanf.c - fscanf, getch, ungetch */

#ifndef EMPTY
#define EMPTY (-1)
#endif
#ifndef EOF
#define EOF   (-2)
#endif

extern int getc(int);

static int getch(int, int);
static int ungetch(int, int);
extern int _doscan(register char *, register int **,
                   int (*getc) (int, int), int (*ungetc) (int, int), int,
                   int);

/*------------------------------------------------------------------------
 *  fscanf  -  Read from a device (file) according to a format.
 *                         Return result of _doscan.
 *------------------------------------------------------------------------
 */
int     fscanf(
          int           dev,            /* device to use                */
          char          *fmt,           /* format string                */
          int           args            /* num of args in format        */
        )
{
    int buf;

    buf = EMPTY;
    return (_doscan
            (fmt, (int **)&args, getch, ungetch, dev, (int)(int)&buf));
}

/*------------------------------------------------------------------------
 *  getch  -  Get a character from a device with pushback.
 *------------------------------------------------------------------------
 */
static int      getch(
                  int           dev,    /* device to use                */
                  int           abuf    /* buffer to use                */
                )
{
    int *buf = (int *)abuf;

    if (*buf != EOF && *buf != EMPTY)
    {
        *buf = getc(dev);
    }
/*      if( *buf != EOF ) */
/*      { *buf = control(dev, TTY_IOC_NEXTC, 0, 0); } */
    return (*buf);
}

/*------------------------------------------------------------------------
 *  ungetch  -  Pushback a character for getch.
 *------------------------------------------------------------------------
 */
static int      ungetch(
                  int           dev,    /* device to use                */
                  int           abuf    /* buffer to use                */
                )
{
    int *buf = (int *)abuf;

    *buf = EMPTY;
    return (*buf);
}