path: root/libc/stdio/scanf.c

#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdarg.h>

#ifdef L_scanf
#ifdef __STDC__
int scanf(const char *fmt, ...)
#else
int scanf(fmt, va_alist)
__const char *fmt;
va_dcl
#endif
{
	va_list ptr;
	int rv;

	va_start(ptr, fmt);
	rv = vfscanf(stdin, fmt, ptr);
	va_end(ptr);
	return rv;
}
#endif

#ifdef L_sscanf
#ifdef __STDC__
int sscanf(const char *sp, const char *fmt, ...)
#else
int sscanf(sp, fmt, va_alist)
__const char *sp;
__const char *fmt;
va_dcl
#endif
{
	FILE string[1] = {
		{0, (char *) (unsigned) -1, 0, 0, (char *) (unsigned) -1, -1,
		 _IOFBF | __MODE_READ}
	};

	va_list ptr;
	int rv;

	va_start(ptr, fmt);
	string->bufpos = (unsigned char *) ((void *) sp);
	rv = vfscanf(string, fmt, ptr);
	va_end(ptr);
	return rv;
}
#endif

#ifdef L_fscanf
#ifdef __STDC__
int fscanf(FILE * fp, const char *fmt, ...)
#else
int fscanf(fp, fmt, va_alist)
FILE *fp;
__const char *fmt;
va_dcl
#endif
{
	va_list ptr;
	int rv;

	va_start(ptr, fmt);
	rv = vfscanf(fp, fmt, ptr);
	va_end(ptr);
	return rv;
}
#endif

#ifdef L_vscanf
int vscanf(fmt, ap)
__const char *fmt;
va_list ap;
{
	return vfscanf(stdin, fmt, ap);
}
#endif

#ifdef L_vsscanf
int vsscanf(__const char *sp, __const char *fmt, va_list ap)
{
	FILE string[1] = {
		{0, (char *) (unsigned) -1, 0, 0, (char *) (unsigned) -1, -1,
		 _IOFBF | __MODE_READ}
	};

	string->bufpos = (unsigned char *) ((void *) sp);
	return vfscanf(string, fmt, ap);
}
#endif

#ifdef L_vfscanf

#if FLOATS
int _vfscanf_fp_ref = 1;
#else
int _vfscanf_fp_ref = 0;
#endif

/* #define	skip()	do{c=getc(fp); if (c<1) goto done;}while(isspace(c))*/

#define	skip()	while(isspace(c)) { if ((c=getc(fp))<1) goto done; }

#if FLOATS
/* fp scan actions */
#define F_NADA	0				/* just change state */
#define F_SIGN	1				/* set sign */
#define F_ESIGN	2				/* set exponent's sign */
#define F_INT	3				/* adjust integer part */
#define F_FRAC	4				/* adjust fraction part */
#define F_EXP	5				/* adjust exponent part */
#define F_QUIT	6

#define NSTATE	8
#define FS_INIT		0			/* initial state */
#define FS_SIGNED	1			/* saw sign */
#define FS_DIGS		2			/* saw digits, no . */
#define FS_DOT		3			/* saw ., no digits */
#define FS_DD		4			/* saw digits and . */
#define FS_E		5			/* saw 'e' */
#define FS_ESIGN	6			/* saw exp's sign */
#define FS_EDIGS	7			/* saw exp's digits */

#define FC_DIG		0
#define FC_DOT		1
#define FC_E		2
#define FC_SIGN		3

/* given transition,state do what action? */
int fp_do[][NSTATE] = {
	{F_INT, F_INT, F_INT,
	 F_FRAC, F_FRAC,
	 F_EXP, F_EXP, F_EXP},		/* see digit */
	{F_NADA, F_NADA, F_NADA,
	 F_QUIT, F_QUIT, F_QUIT, F_QUIT, F_QUIT},	/* see '.' */
	{F_QUIT, F_QUIT,
	 F_NADA, F_QUIT, F_NADA,
	 F_QUIT, F_QUIT, F_QUIT},	/* see e/E */
	{F_SIGN, F_QUIT, F_QUIT, F_QUIT, F_QUIT,
	 F_ESIGN, F_QUIT, F_QUIT},	/* see sign */
};

/* given transition,state what is new state? */
int fp_ns[][NSTATE] = {
	{FS_DIGS, FS_DIGS, FS_DIGS,
	 FS_DD, FS_DD,
	 FS_EDIGS, FS_EDIGS, FS_EDIGS},	/* see digit */
	{FS_DOT, FS_DOT, FS_DD,
	 },							/* see '.' */
	{0, 0,
	 FS_E, 0, FS_E,
	 },							/* see e/E */
	{FS_SIGNED, 0, 0, 0, 0,
	 FS_ESIGN, 0, 0},			/* see sign */
};

/* which states are valid terminators? */
int fp_sval[NSTATE] = {
	0, 0, 1, 0, 1, 0, 0, 1
};
#endif

int vfscanf(fp, fmt, ap)
register FILE *fp;
register const char *fmt;
va_list ap;

{
	register long n;
	register int c, width, lval, cnt = 0;
	int store, neg, base, wide1, endnull, rngflag, c2;
	register unsigned char *p;
	unsigned char delim[128], digits[17], *q;

#if FLOATS
	long frac, expo;
	int eneg, fraclen, fstate, trans;
	double fx, fp_scan();
#endif

	if (!*fmt)
		return (0);

	c = getc(fp);
	while (c > 0) {
		store = 0;
		if (*fmt == '%') {
			n = 0;
			width = -1;
			wide1 = 1;
			base = 10;
			lval = (sizeof(long) == sizeof(int));

			store = 1;
			endnull = 1;
			neg = -1;

			strcpy(delim, "\011\012\013\014\015 ");
			strcpy(digits, "0123456789ABCDEF");

			if (fmt[1] == '*') {
				endnull = store = 0;
				++fmt;
			}

			while (isdigit(*++fmt)) {	/* width digit(s) */
				if (width == -1)
					width = 0;
				wide1 = width = (width * 10) + (*fmt - '0');
			}
			--fmt;
		  fmtnxt:
			++fmt;
			switch (tolower(*fmt)) {	/* tolower() is a MACRO! */
			case '*':
				endnull = store = 0;
				goto fmtnxt;

			case 'l':			/* long data */
				lval = 1;
				goto fmtnxt;
			case 'h':			/* short data */
				lval = 0;
				goto fmtnxt;

			case 'i':			/* any-base numeric */
				base = 0;
				goto numfmt;

			case 'b':			/* unsigned binary */
				base = 2;
				goto numfmt;

			case 'o':			/* unsigned octal */
				base = 8;
				goto numfmt;

			case 'x':			/* unsigned hexadecimal */
				base = 16;
				goto numfmt;

			case 'd':			/* SIGNED decimal */
				neg = 0;
				/* FALL-THRU */

			case 'u':			/* unsigned decimal */
			  numfmt:skip();

				if (isupper(*fmt))
					lval = 1;

				if (!base) {
					base = 10;
					neg = 0;
					if (c == '%') {
						base = 2;
						goto skip1;
					} else if (c == '0') {
						c = getc(fp);
						if (c < 1)
							goto savnum;
						if ((c != 'x')
							&& (c != 'X')) {
							base = 8;
							digits[8] = '\0';
							goto zeroin;
						}
						base = 16;
						goto skip1;
					}
				}

				if ((neg == 0) && (base == 10)
					&& ((neg = (c == '-')) || (c == '+'))) {
				  skip1:
					c = getc(fp);
					if (c < 1)
						goto done;
				}

				digits[base] = '\0';
				p = ((unsigned char *)
					 strchr(digits, toupper(c)));

				if ((!c || !p) && width)
					goto done;

				while (p && width-- && c) {
					n = (n * base) + (p - digits);
					c = getc(fp);
				  zeroin:
					p = ((unsigned char *)
						 strchr(digits, toupper(c)));
				}
			  savnum:
				if (store) {
					if (neg == 1)
						n = -n;
					if (lval)
						*va_arg(ap, long *) = n;

					else
						*va_arg(ap, short *) = n;

					++cnt;
				}
				break;

#if FLOATS
			case 'e':			/* float */
			case 'f':
			case 'g':
				skip();
				fprintf(stderr, "LIBM:SCANF");

				if (isupper(*fmt))
					lval = 1;

				fstate = FS_INIT;
				neg = 0;
				eneg = 0;
				n = 0;
				frac = 0;
				expo = 0;
				fraclen = 0;

				while (c && width--) {
					if (c >= '0' && c <= '9')
						trans = FC_DIG;
					else if (c == '.')
						trans = FC_DOT;
					else if (c == '+' || c == '-')
						trans = FC_SIGN;
					else if (tolower(c) == 'e')
						trans = FC_E;
					else
						goto fdone;

					switch (fp_do[trans][fstate]) {
					case F_SIGN:
						neg = (c == '-');
						break;
					case F_ESIGN:
						eneg = (c == '-');
						break;
					case F_INT:
						n = 10 * n + (c - '0');
						break;
					case F_FRAC:
						frac = 10 * frac + (c - '0');
						fraclen++;
						break;
					case F_EXP:
						expo = 10 * expo + (c - '0');
						break;
					case F_QUIT:
						goto fdone;
					}
					fstate = fp_ns[trans][fstate];
					c = getc(fp);
				}

			  fdone:
				if (!fp_sval[fstate])
					goto done;
				if (store) {
					fx = fp_scan(neg, eneg, n, frac, expo, fraclen);
					if (lval)
						*va_arg(ap, double *) = fx;

					else
						*va_arg(ap, float *) = fx;

					++cnt;
				}
				break;
#else
			case 'e':			/* float */
			case 'f':
			case 'g':
				fprintf(stderr, "LIBC:SCANF");
				exit(-1);
#endif

			case 'c':			/* character data */
				width = wide1;
				lval = endnull = 0;
				delim[0] = '\0';
				goto strproc;

			case '[':			/* string w/ delimiter set */

				/* get delimiters */
				p = delim;

				if (*++fmt == '^') {
					fmt++;
					lval = 0;
				} else
					lval = 1;

				rngflag = 2;
				if ((*fmt == ']') || (*fmt == '-')) {
					*p++ = *fmt++;
					rngflag = 0;
				}

				while (*fmt != ']') {
					if (*fmt == '\0')
						goto done;
					switch (rngflag) {
					case 1:
						c2 = *(p - 2);
						if (c2 <= *fmt) {
							p -= 2;
							while (c2 < *fmt)
								*p++ = c2++;
							rngflag = 2;
							break;
						}
						/* fall thru intentional */

					case 0:
						rngflag = (*fmt == '-');
						break;

					case 2:
						rngflag = 0;
					}

					*p++ = *fmt++;
				}

				*p = '\0';
				goto strproc;

			case 's':			/* string data */
				lval = 0;
				skip();
			  strproc:
				/* process string */
				p = va_arg(ap, unsigned char *);

				/* if the 1st char fails, match fails */
				if (width) {
					q = ((unsigned char *)
						 strchr(delim, c));
					if ((c < 1) || lval == (q == 0)) {
						if (endnull)
							*p = '\0';
						goto done;
					}
				}

				for (;;) {		/* FOREVER */
					if (store)
						*p++ = c;
					if (((c = getc(fp)) < 1) || (--width == 0))
						break;

					q = ((unsigned char *)
						 strchr(delim, c));
					if (lval == (q == 0))
						break;
				}

				if (store) {
					if (endnull)
						*p = '\0';
					++cnt;
				}
				break;

			case '\0':			/* early EOS */
				--fmt;
				/* FALL THRU */

			default:
				goto cmatch;
			}
		} else if (isspace(*fmt)) {	/* skip whitespace */
			skip();
		} else {				/* normal match char */
		  cmatch:
			if (c != *fmt)
				break;
			c = getc(fp);
		}

		if (!*++fmt)
			break;
	}

  done:						/* end of scan */
	if ((c == EOF) && (cnt == 0))
		return (EOF);

	if (c != EOF)
		ungetc(c, fp);
	return (cnt);
}

#endif