scanf.c

mips架构的bootloader,99左右的版本 但源代码现在没人更新了

/*************************************************************
 * File: lib/scanf.c
 * Purpose: Part of C runtime library
 * Author: Phil Bunce ([e-mail])
 * Revision History:
 *	970304	Start of revision history
 */

#include "varargs.h"
#include "stdio.h"
#include <string.h>

/*
** fscanf --\    sscanf --\
**          |		  |
**  scanf --+-- vfscanf ----- vsscanf
**
** This not been very well tested.. it probably has bugs
*/

#define ISSPACE " \t\n\r\f\v"

#ifdef TEST
main(argc,argv)
int argc;
char *argv[];
{
char buf[40],s[30];
int a,b,n,i;
char fmt[80];

strcpy(fmt,"%d %d");
for (i=1;i<argc;i++) {
	if (i > 1) strcat(fmt," ");
	else *fmt = 0;
	strcat(fmt,argv[i]);
	}

printf("fmt=[%s]\n",fmt);
for (;;) {
	printf("> ");
	a = b = 0;
	n = scanf(fmt,&a,&b);
	printf("n=%d ",n);
	if (n == 0) break;
	if (n >= 1) printf("a=%d[%x] ",a,a);
	if (n >= 2) printf("b=%d[%x] ",b,b);
	printf("\n");
	}
printf("\n");
}

#endif


/*************************************************************
*  scanf(fmt,va_alist) 
*/
scanf(fmt,va_alist) 
char *fmt;
va_dcl
{
va_list ap;
int count;

va_start(ap);
count = vfscanf(stdin,fmt,ap);
va_end(ap);
return(count);
}

/*************************************************************
*  sscanf(buf,fmt,va_alist)
*/
sscanf(buf,fmt,va_alist)
char *buf,*fmt;
va_dcl
{
va_list ap;
int count;

if (!buf) return(0); /* defensive programming */
va_start(ap);
count = vsscanf(buf,fmt,ap);
va_end(ap);
return(count);
}

/*************************************************************
*  vfscanf(fp,fmt,ap) 
*/
vfscanf(fp,s,ap) 
FILE *fp;
char *s;
va_list ap;
{
int count,noassign,width,base,lflag,c,i;
char *t,tmp[MAXLN];

count = noassign = width = lflag = 0;
c = getc(fp);
while (*s) {
	while (isspace(*s)) s++;
	if (*s == '%') {
		s++;
		for (;*s;s++) {
			if (strchr("dibouxcsefg%",*s)) break;
			if (*s == '*') noassign = 1;
			else if (*s == 'l' || *s == 'L') lflag = 1;
			else if (*s >= '1' && *s <= '9') {
				for (t=s;isdigit(*s);s++) ;
				strncpy(tmp,t,s-t);
				atob(&width,tmp,10);
				s--;
				}
			}
		if (*s == 's') {
			while (isspace(c)) c = getc(fp);
			for (i=0,t=va_arg(ap,char *);;i++) {
				if (!width && isspace(c)) break;
				if (width && i >= width) break;
				if (!noassign) *t++ = c;
				c = getc(fp);
				}
			if (!noassign) count++, *t = 0;
			}
		else if (*s == 'c') {
			if (!width) width = 1;
			for (i=0,t=va_arg(ap,char *);i<width;i++) {
				if (!noassign) *t++ = c;
				c = getc(fp);
				}
			if (!noassign) count++, *t = 0;
			}
		else if (strchr("dobxu",*s)) {
			while (isspace(c)) c = getc(fp);
			if (*s == 'd' || *s == 'u') base = 10;
			else if (*s == 'x') base = 16;
			else if (*s == 'o') base = 8;
			else if (*s == 'b') base = 2;
			for (i=0,t=tmp;;i++) {
				if (width && i >= width) break;
				if (!width) {
					if (isspace(*(s+1)) || *(s+1) == 0) {
						if (isspace(c)) break;
						}
					else if (c == *(s+1)) break;
					}
				*t++ = c;
				c = getc(fp);
				}
			*t = 0;
			if (!noassign) {
				if (atob(va_arg(ap,int *),tmp,base)) count++;
				}
			}
		width = noassign = lflag = 0;
		s++;
		}
	else {
		while (isspace(c)) c = getc(fp);
		if (*s != c) break;
		else s++,c=getc(fp);
		}
	}
ungetc(c,fp);
return(count);
}

/*************************************************************
*  vsscanf(buf,fmt,ap)
*/
vsscanf(buf,s,ap)
char *buf,*s;
va_list ap;
{
int count,noassign,width,base,lflag;
char *t,tmp[MAXLN];

count = noassign = width = lflag = 0;
while (*s && *buf) {
	while (isspace(*s)) s++;
	if (*s == '%') {
		s++;
		for (;*s;s++) {
			if (strchr("dibouxcsefg%",*s)) break;
			if (*s == '*') noassign = 1;
			else if (*s == 'l' || *s == 'L') lflag = 1;
			else if (*s >= '1' && *s <= '9') {
				for (t=s;isdigit(*s);s++) ;
				strncpy(tmp,t,s-t);
				atob(&width,tmp,10);
				s--;
				}
			}
		if (*s == 's') {
			while (isspace(*buf)) buf++;
			if (!width) width = strcspn(buf,ISSPACE);
			if (!noassign) {
				strncpy(va_arg(ap,char *),buf,width);
				count++;
				}
			buf += width;
			}
		else if (*s == 'c') {
			if (!width) width = 1;
			if (!noassign) {
				strncpy(va_arg(ap,char *),buf,width);
				count++;
				}
			buf += width;
			}
		else if (strchr("dobxu",*s)) {
			while (isspace(*buf)) buf++;
			if (*s == 'd' || *s == 'u') base = 10;
			else if (*s == 'x') base = 16;
			else if (*s == 'o') base = 8;
			else if (*s == 'b') base = 2;
			if (!width) {
				if (isspace(*(s+1)) || *(s+1) == 0) 
					width = strcspn(buf,ISSPACE);
				else
					width = strchr(buf,*(s+1))-buf;
				}
			strncpy(tmp,buf,width);
			buf += width;
			if (!noassign) {
				if (atob(va_arg(ap,int *),tmp,base)) count++;
				}
			}
		width = noassign = lflag = 0;
		s++;
		}
	else {
		while (isspace(*buf)) buf++;
		if (*s != *buf) break;
		else s++,buf++;
		}
	}
return(count);
}