scanf.c

linux下用PCMCIA无线网卡虚拟无线AP的程序源码

					}
					/* ok -- back to common work */
					if (sc.width <= 0) {
						goto done;
					}
					if (store) {
						b = va_arg(ap, unsigned char *);
					} else {
						b = buf;
					}
					cc = scan_getc(&sc);
					if (cc <= 0) {
						scan_ungetc(&sc);
						goto done; /* return EOF if cnt == 0 */
					}
					i = 0;
					while ((cc>0) && (scanset[cc] != invert)) {
						i = 1; /* yes, we stored something */
						*b = cc;
						b += store;
						cc = scan_getc(&sc);
					}
					if (i==0) {
						scan_ungetc(&sc);
						goto done; /* return cnt */
					}
					if (*p != 'c') { /* nul-terminate the stored string */
						*b = 0;
					}
					cnt += store;
					goto nextfmt;
				}
				if (p-spec < 12) { /* o,u,p,x,X,i,d - (un)signed integer */
					if (*p == 'p') {
						/* assume pointer same size as int or long. */
						lval = (sizeof(char *) == sizeof(long));
					}
					usflag = ((p-spec) < 10); /* (1)0 if (un)signed */
					base = radix[(int)(p-spec) - 5];
					b = buf;
					if (sc.width <= 0) {
						goto done;
					}
					cc = scan_getc(&sc);
					if ((cc == '+') || (cc == '-')) { /* Handle leading sign.*/
						*b++ = cc;
						cc = scan_getc(&sc);
					}
					if (cc == '0') { /* Possibly set base and handle prefix. */
						if ((base == 0) || (base == 16)) {
							cc = scan_getc(&sc);
							if ((cc == 'x') || (cc == 'X')) {
								/* We're committed to base 16 now. */
								base = 16;
								cc = scan_getc(&sc);
							} else { /* oops... back up */
								scan_ungetc(&sc);
								cc = '0';
								if (base == 0) {
									base = 8;
								}
							}
						}
					}
					if (base == 0) { /* Default to base 10 */
						base = 10;
					}
					/* At this point, we're ready to start reading digits. */
					if (cc == '0') {
						*b++ = cc; /* Store first leading 0 */
						do {	/*     but ignore others. */
							cc = scan_getc(&sc);
						} while (cc == '0');
					}
					while (valid_digit(cc,base)) { /* Now for nonzero digits.*/
						if (b - buf < MAX_DIGITS) {
							*b++ = cc;
						}
						cc = scan_getc(&sc);
					}
					*b = 0;	/* null-terminate */
					if ((b == buf) || (*--b == '+') || (*b == '-')) {
						scan_ungetc(&sc);
						goto done; /* No digits! */
					}
					if (store) {
						if (*buf == '-') {
							usflag = 0;
						}
						uv = STRTO_L_(buf, NULL, base, usflag);
						vp = va_arg(ap, void *);
						switch (lval) {
							case 2:	/* If no long long, treat as long . */
#ifdef __UCLIBC_HAS_LONG_LONG__
								*((unsigned long long *)vp) = uv;
								break;
#endif
							case 1:
#if ULONG_MAX == UINT_MAX
							case 0:	/* int and long int are the same */
#endif
#ifdef __UCLIBC_HAS_LONG_LONG__
								if (usflag) {
									if (uv > ULONG_MAX) {
										uv = ULONG_MAX;
									}
								} else if (((V_TYPE)uv) > LONG_MAX) {
									uv = LONG_MAX;
								} else if (((V_TYPE)uv) < LONG_MIN) {
									uv = (UV_TYPE) LONG_MIN;
								}
#endif
								*((unsigned long *)vp) = (unsigned long)uv;
								break;
#if ULONG_MAX != UINT_MAX
							case 0:	/* int and long int are different */
								if (usflag) {
									if (uv > UINT_MAX) {
										uv = UINT_MAX;
									}
								} else if (((V_TYPE)uv) > INT_MAX) {
									uv = INT_MAX;
								} else if (((V_TYPE)uv) < INT_MIN) {
									uv = (UV_TYPE) INT_MIN;
								}
								*((unsigned int *)vp) = (unsigned int)uv;
								break;
#endif
							case -1:
								if (usflag) {
									if (uv > USHRT_MAX) {
										uv = USHRT_MAX;
									}
								} else if (((V_TYPE)uv) > SHRT_MAX) {
									uv = SHRT_MAX;
								} else if (((V_TYPE)uv) < SHRT_MIN) {
									uv = (UV_TYPE) SHRT_MIN;
								}
								*((unsigned short *)vp) = (unsigned short)uv;
								break;
							case -2:
								if (usflag) {
									if (uv > UCHAR_MAX) {
										uv = UCHAR_MAX;
									}
								} else if (((V_TYPE)uv) > CHAR_MAX) {
									uv = CHAR_MAX;
								} else if (((V_TYPE)uv) < CHAR_MIN) {
									uv = (UV_TYPE) CHAR_MIN;
								}
								*((unsigned char *)vp) = (unsigned char) uv;
								break;
							default:
								assert(0);
						}
						++cnt;
					}
					goto nextfmt;
				}
#ifdef __UCLIBC_HAS_FLOATS__
				else {			/* floating point */
					if (sc.width <= 0) {
						goto done;
					}
					if (__strtold(&ld, &sc)) { /* Success! */
						if (store) {
							vp = va_arg(ap, void *);
							switch (lval) {
								case 2:
									*((long double *)vp) = ld;
									break;
								case 1:
									*((double *)vp) = (double) ld;
									break;
								case 0:
									*((float *)vp) = (float) ld;
									break;
								default: /* Illegal qualifier! */
									assert(0);
									goto done;
							}
							++cnt;
						}
						goto nextfmt;
					}
				}
#else
				assert(0);
#endif
				goto done;
			}
			/* Unrecognized specifier! */
			goto done;
		} if (isspace(*fmt)) {	/* Consume all whitespace. */
			while (isspace(scan_getc_nw(&sc)))
				{}
		} else {				/* Match the current fmt char. */
		matchchar:
			if (scan_getc_nw(&sc) != *fmt) {
				goto done;
			}
			scan_getc_nw(&sc);
		}
	nextfmt:
		scan_ungetc(&sc);
		++fmt;
	}

  done:						/* end of scan */
	kill_scan_cookie(&sc);

	if ((sc.ungot_char <= 0) && (cnt == 0) && (*fmt)) {
		return (EOF);
	}

	return (cnt);
}

/*****************************************************************************/
#ifdef __UCLIBC_HAS_FLOATS__

#include <float.h>

#define MAX_SIG_DIGITS 20
#define MAX_IGNORED_DIGITS 2000
#define MAX_ALLOWED_EXP (MAX_SIG_DIGITS + MAX_IGNORED_DIGITS + LDBL_MAX_10_EXP)

#if LDBL_DIG > MAX_SIG_DIGITS
#error need to adjust MAX_SIG_DIGITS
#endif

#include <limits.h>
#if MAX_ALLOWED_EXP > INT_MAX
#error size assumption violated for MAX_ALLOWED_EXP
#endif

int __strtold(long double *ld, struct scan_cookie *sc)
{
    long double number;
    long double p10;
    int exponent_power;
    int exponent_temp;
    int negative;
    int num_digits;
    int since_decimal;
	int c;

	c = scan_getc(sc);				/* Decrements width. */

    negative = 0;
    switch(c) {					/* Handle optional sign. */
		case '-': negative = 1;	/* Fall through to get next char. */
		case '+': c = scan_getc(sc);
    }

    number = 0.;
    num_digits = -1;
    exponent_power = 0;
    since_decimal = INT_MIN;

 LOOP:
    while (isdigit(c)) {		/* Process string of digits. */
		++since_decimal;
		if (num_digits < 0) {	/* First time through? */
			++num_digits;		/* We've now seen a digit. */
		}
		if (num_digits || (c != '0')) { /* had/have nonzero */
			++num_digits;
			if (num_digits <= MAX_SIG_DIGITS) { /* Is digit significant? */
				number = number * 10. + (c - '0');
			}
		}
		c = scan_getc(sc);
    }

    if ((c == '.') && (since_decimal < 0)) { /* If no previous decimal pt, */
		since_decimal = 0;		/* save position of decimal point */
		c = scan_getc(sc);			/* and process rest of digits */
		goto LOOP;
    }

    if (num_digits<0) {			/* Must have at least one digit. */
		goto FAIL;
    }

    if (num_digits > MAX_SIG_DIGITS) { /* Adjust exp for skipped digits. */
		exponent_power += num_digits - MAX_SIG_DIGITS;
    }

    if (since_decimal >= 0) {		/* Adjust exponent for decimal point. */
		exponent_power -= since_decimal;
    }

    if (negative) {				/* Correct for sign. */
		number = -number;
		negative = 0;			/* Reset for exponent processing below. */
    }

    /* Process an exponent string. */
    if (c == 'e' || c == 'E') {
		c = scan_getc(sc);
		switch(c) {				/* Handle optional sign. */
			case '-': negative = 1;	/* Fall through to get next char. */
			case '+': c = scan_getc(sc);
		}

		num_digits = 0;
		exponent_temp = 0;
		while (isdigit(c)) {	/* Process string of digits. */
			if (exponent_temp < MAX_ALLOWED_EXP) { /* overflow check */
				exponent_temp = exponent_temp * 10 + (c - '0');
			}
			c = scan_getc(sc);
			++num_digits;
		}

		if (num_digits == 0) {	/* Were there no exp digits? */
			goto FAIL;
		} /* else */
		if (negative) {
			exponent_power -= exponent_temp;
		} else {
			exponent_power += exponent_temp;
		}
    }

    if (number != 0.) {
		/* Now scale the result. */
		exponent_temp = exponent_power;
		p10 = 10.;

		if (exponent_temp < 0) {
			exponent_temp = -exponent_temp;
		}

		while (exponent_temp) {
			if (exponent_temp & 1) {
				if (exponent_power < 0) {
					number /= p10;
				} else {
					number *= p10;
				}
			}
			exponent_temp >>= 1;
			p10 *= p10;
		}
	}
	*ld = number;
	return 1;

 FAIL:
	scan_ungetc(sc);
	return 0;
}
#endif /* __UCLIBC_HAS_FLOATS__ */
#endif