printf.c

linux下用PCMCIA无线网卡虚拟无线AP的程序源码

int vfnprintf(FILE * op, size_t max_size, const char *fmt, va_list ap)
{
	int i, cnt, lval, len;
	char *p;
	const char *fmt0;
	int buffer_mode;
	int preci, width;
#define upcase i
	int radix, dpoint /*, upcase*/;
#if defined(__UCLIBC_HAS_LONG_LONG__)
	char tmp[65];
#else
	char tmp[33];
#endif
	char flag[sizeof(spec)];

	cnt = 0;

	/* This speeds things up a bit for line unbuffered */
	buffer_mode = (op->mode & __MODE_BUF);
	op->mode &= (~__MODE_BUF);

	while (*fmt) {
		if (*fmt == '%') {
			fmt0 = fmt;			/* save our position in case of bad format */
			++fmt;
			width = -1;			/* min field width */
			preci = -5;			/* max string width or mininum digits */
			radix = 10;			/* number base */
			dpoint = 0;			/* found decimal point */
#if INT_MAX != LONG_MAX
			lval = 0;			/* sizeof(int) != sizeof(long) */
#else
			lval = 1;			/* sizeof(int) == sizeof(long) */
#endif

			tmp[1] = 0;			/* set things up for %c -- better done here */

			/* init flags */
			for (p =(char *) spec ; *p ; p++) {
				flag[p-spec] = '\0';
			}
			flag[FLAG_0_PAD] = ' ';

			/* process optional flags */
			for (p = (char *)spec ; *p ; ) {
				if (*fmt == *p) {
					flag[p-spec] = *fmt++;
					p = (char *)spec; /* restart scan */
				} else {
					p++;
				}
			}
			
			if (!flag[FLAG_PLUS]) {
				flag[FLAG_PLUS] = flag[FLAG_SPACE];
			}

			/* process optional width and precision */
			do {
				if (*fmt == '.') {
					++fmt;
					dpoint = 1;
				}
				if (*fmt == '*') {	/* parameter width value */
					++fmt;
					i = va_arg(ap, int);
				} else {
					for ( i = 0 ; (*fmt >= '0') && (*fmt <= '9') ; ++fmt ) {
						i = (i * 10) + (*fmt - '0');
					}
				}

				if (dpoint) {
					preci = i;
					if (i<0) {
						preci = -5;
					}
				} else {
					width = i;
					if (i<0) {
						width = -i;
						flag[FLAG_MINUS_LJUSTIFY] = 1;
					}
				}
			} while ((*fmt == '.') && !dpoint );

			/* process optional qualifier */
			for (p = (char *) qual ; *p ; p++) {
				if (*p == *fmt) {
					lval = p - qual;
					++fmt;
#if defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR
					if ((*p == 'l') && (*fmt == *p)) {
						++lval;
						++fmt;
					}
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR */
				}
			}

#if WANT_GNU_ERRNO
			if (*fmt == 'm') {
				flag[FLAG_PLUS] = '\0';
				flag[FLAG_0_PAD] = ' ';
				p = strerror(errno);
				goto print;
			}
#endif

			/* process format specifier */
			for (p = (char *) u_spec ; *p ; p++) {
				if (*fmt != *p) continue;
				if (p-u_spec < 1) {	/* print a % */
					goto charout;
				}
				if (p-u_spec < 2) {	/* store output count in int ptr */
					*(va_arg(ap, int *)) = cnt;
					goto nextfmt;
				}
				if (p-u_spec < 8) { /* unsigned conversion */
					radix = u_radix[p-u_spec-2];
					upcase = ((int)'x') - *p;
					if (*p == 'p') {
						lval = (sizeof(char *) == sizeof(long));
						upcase = 0;
						flag[FLAG_HASH] = 'p';
					}
#if defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR
					if (lval >= 2) {
#if defined(__UCLIBC_HAS_LONG_LONG__)
						p = __ulltostr(tmp + sizeof(tmp) - 1,
									   va_arg(ap, unsigned long long),
									   radix, upcase);
#else
						(void) va_arg(ap, unsigned long long);	/* cary on */
						p = (char *) ll_err;
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) */
					} else {
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR */
#if UINT_MAX != ULONG_MAX
						/* sizeof(unsigned int) != sizeof(unsigned long) */
						p = __ultostr(tmp + sizeof(tmp) - 1, (unsigned long)
									  ((lval)
									   ? va_arg(ap, unsigned long)
									   : va_arg(ap, unsigned int)),
									  radix, upcase);
#else
						/* sizeof(unsigned int) == sizeof(unsigned long) */
						p = __ultostr(tmp + sizeof(tmp) - 1, (unsigned long)
									  va_arg(ap, unsigned long),
									  radix, upcase);
#endif
#if defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR
					}
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR */
					flag[FLAG_PLUS] = '\0';	/* meaningless for unsigned */
					if (*p != '0') { /* non-zero */
						if (flag[FLAG_HASH]) {
							if (radix == 8) {
								*--p = '0';	/* add leadding zero */
							} else if (radix != 10) { /* either 2 or 16 */
								flag[FLAG_PLUS] = '0';
								*--p = 'b';
								if (radix == 16) {
									*p = 'x';
									if (*fmt == 'X') {
										*p = 'X';
									}
								}
							}
						}
					} else if (flag[FLAG_HASH] == 'p') { /* null pointer */
						p = "(nil)";
					}
				} else if (p-u_spec < 10) { /* signed conversion */
#if defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR
					if (lval >= 2) {
#if defined(__UCLIBC_HAS_LONG_LONG__)
						p = __lltostr(tmp + sizeof(tmp) - 1,
									  va_arg(ap, long long), 10, 0);
#else
						(void) va_arg(ap, long long); /* carry on */
						p = (char *) ll_err;
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) */
					} else {
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR */
#if INT_MAX != LONG_MAX
						/* sizeof(int) != sizeof(long) */
						p = __ltostr(tmp + sizeof(tmp) - 1, (long)
									 ((lval)
									  ? va_arg(ap, long)
									  : va_arg(ap, int)), 10, 0);
#else
						/* sizeof(int) == sizeof(long) */
						p = __ltostr(tmp + sizeof(tmp) - 1, (long)
									 va_arg(ap, long), 10, 0);
#endif
#if defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR
					}
#endif /* defined(__UCLIBC_HAS_LONG_LONG__) || WANT_LONG_LONG_ERROR */
				} else if (p-u_spec < 12) {	/* character or string */
					flag[FLAG_PLUS] = '\0';
					flag[FLAG_0_PAD] = ' ';
					if (*p == 'c') {	/* character */
						p = tmp;
						*p = va_arg(ap, int);
						/* This takes care of the "%c",0 case */
						len = 1;
						goto print_len_set;
					} else {	/* string */
						p = va_arg(ap, char *);
						if (!p) {
							p = "(null)";
						}
					}
#if defined(__UCLIBC_HAS_FLOATS__) || WANT_FLOAT_ERROR
				} else if (p-u_spec < 27) {		/* floating point */
#endif /* defined(__UCLIBC_HAS_FLOATS__) || WANT_FLOAT_ERROR */
#if defined(__UCLIBC_HAS_FLOATS__)
					if (preci < 0) {
						preci = 6;
					}
					cnt += __dtostr(op, 
									(max_size > cnt ? max_size - cnt : 0),
									(long double) ((lval > 1)
									 ? va_arg(ap, long double)
									 : va_arg(ap, double)),
									flag, width,  preci, *fmt);
					goto nextfmt;
#elif WANT_FLOAT_ERROR
					(void) ((lval > 1) ? va_arg(ap, long double)
							: va_arg(ap, double)); /* carry on */
					p = (char *) dbl_err;
#endif /* defined(__UCLIBC_HAS_FLOATS__) */
				}

#if WANT_GNU_ERRNO
			print:
#endif
				{				/* this used to be printfield */
					/* cheaper than strlen call */
					for ( len = 0 ; p[len] ; len++ ) { }
				print_len_set:
					if ((*p == '-')
#if WANT_GNU_ERRNO
						&& (*fmt != 'm')
#endif
						&& (*fmt != 's')) {
						flag[FLAG_PLUS] = *p++;
						--len;
					}
				    if (flag[FLAG_PLUS]) {
						++len;
						++preci;
						if (flag[FLAG_PLUS] == '0') { /* base 16 */
							++preci; /* account for x or X */
						}
					}

					if (preci >= 0) {
						if ((*fmt == 's')
#if WANT_GNU_ERRNO
						|| (*fmt == 'm')
#endif
						) {
							if (len > preci) {
								len = preci;
							} else {
								preci = len;
							}
						}
						preci -= len;
						if (preci < 0) {
							preci = 0;
						}
						width -= preci;
					}

					width -= len;
					if (width < 0) {
						width = 0;
					}

					if (preci < 0) {
						preci = 0;
						if (!flag[FLAG_MINUS_LJUSTIFY]
							/* && flag[FLAG_PLUS] */
							&& (flag[FLAG_0_PAD] == '0')) { 
							preci = width;
							width = 0;
						}
					}

					while (width + len + preci) {
						unsigned char ch;
						/* right padding || left padding */
						if ((!len && !preci)
							|| (width && !flag[FLAG_MINUS_LJUSTIFY])) {
							ch = ' ';
							--width;
						} else if (flag[FLAG_PLUS]) {
							ch = flag[FLAG_PLUS]; /* sign */
							if (flag[FLAG_PLUS]=='0') {	/* base 16 case */
								flag[FLAG_PLUS] = *p++;	/* get the x|X */
							} else {
								flag[FLAG_PLUS] = '\0';
							}
							--len;
						} else if (preci) {
							ch = '0';
							--preci;
						} else {
							ch = *p++; /* main field */
							--len;
						}

						if (++cnt < max_size) {
							putc(ch, op);
						}
						if ((ch == '\n') && (buffer_mode == _IOLBF)) {
							fflush(op);
						}
					}
				}
				goto nextfmt;
			}

			fmt = fmt0;	/* this was an illegal format */
		}

		charout:
		if (++cnt < max_size) {
			putc(*fmt, op);	/* normal char out */
		}
		if ((*fmt == '\n') && (buffer_mode == _IOLBF)) {
			fflush(op);
		}

	nextfmt:
		++fmt;
	}

	op->mode |= buffer_mode;
	if (buffer_mode == _IOLBF) {
		op->bufwrite = op->bufpos;
	}

	if (ferror(op)) {
		cnt = -1;
	}
	return (cnt);
}

#endif