/* sscanf.c - sscanf, sgetch, sungetch */

#define EOF   (-2)

static int sgetch(int, char **);
static int sungetch(int, char **);
extern int _doscan(register char *, register int **,
                   int (*getc) (int, char **),
                   int (*ungetc) (int, char **), int, int);

/*------------------------------------------------------------------------
 *  sscanf  -  Read from a string according to a format.
 *                         Return result of _doscan.
 *------------------------------------------------------------------------
 */
int     sscanf(
          char          *str,           /* String to read from          */
          char          *fmt,           /* Format string                */
          int           args            /* Num of args in format string */
        )
{
    char *s;

    s = str;
    return (_doscan(fmt, (int **)&args, sgetch, sungetch, 0, (int)&s));
}

/*------------------------------------------------------------------------
 *  sgetch  -  Get the next character from a string
 *------------------------------------------------------------------------
 */
static int      sgetch(
                  int           dummy,  /* Dummy unused variable        */
                  char          **cpp   /* String to use                */
                )
{
    return (*(*cpp) == '\0' ? EOF : *(*cpp)++);
}

/*------------------------------------------------------------------------
 *  sungetch  -  Pushback a character in a string
 *------------------------------------------------------------------------
 */
static int      sungetch(
                  int           dummy,  /* Dummy unused variable        */
                  char          **cpp   /* String for pushback          */
                )
{
    return (*(*cpp)--);
}