kolibrios/programs/develop/ktcc/trunk/libc/stdio/fscanf.c

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#include <stdio.h>
void skipspaces(FILE* file)
{
int c;
while(1)
{
c=getc(file);
if (c!=' ' && c!='\r' && c!='\n')
{
ungetc(c,file);
return;
}
}
}
int fscanf(FILE* file,const char* format, ...)
{
int res;
void* arg;
int i;
int c;
int contflag;
int longflag;
int sign;
long long number;
long double rnumber;
char* str;
res=0;
arg=&format;
arg+=sizeof(const char*);
while (*format!='\0')
{
if (*format!='%')
{
c=fgetc(file);
if (c!=*format)
{
fungetc(c,file);
return -1;
}
format++;
continue;
}
contflag=1;
longflag=0;
while (*format && contflag)
{
switch(*format)
{
case '.':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
format++;
continue;
break;
case 'l':
if (longflag==0)
longflag=1;
else
longflag=2;
format++;
break;
case 'L':
longflag=2;
format++;
break;
case 'f':
case 'd':
case 'c':
case 's':
case '%':
contflag=0;
break;
default:
contflag=0;
}
}
if (contflag)
break;
switch(*format)
{
case '%':
c=fgetc(file);
if (c!='%')
{
ungetc(c,file);
return -1;
}
res--;
break;
case 'd':
number=0;
sign=1;
skipspaces(file);
c=fgetc(file);
if (c=='-')
{
sign=-1;
}else if (c!='+')
ungetc(c,file);
contflag=0;
while(1)
{
c=fgetc(file);
if (c>='0' && c<='9')
{
contflag++;
number=number*10+(c-'0');
}else
break;
}
ungetc(c,file);
if (!contflag)
return res;
if (longflag<=1)
{
*((int*)arg)=number;
arg+=sizeof(int);
}else
{
*((long long*)arg)=number;
arg+=sizeof(long long);
}
break;
case 'c':
c=fgetc(file);
if (c==EOF)
return res;
*((char*)arg)=c;
arg+=sizeof(char);
break;
case 's':
skipspaces(file);
contflag=0;
str=*((char**)arg);
arg+=sizeof(char*);
while(1)
{
c=fgetc(file);
if (c==EOF || c==' ' || c=='\n' || c=='\r')
{
ungetc(c,file);
break;
}
*str=c;
str++;
contflag++;
}
if (!contflag)
return res;
break;
case 'f':
skipspaces(file);
// TODO: read real numbers
rnumber=0;
switch (longflag)
{
case 0:
*((float*)arg)=rnumber;
arg+=sizeof(float);
break;
case 1:
*((double*)arg)=rnumber;
arg+=sizeof(double);
break;
case 2:
*((long double*)arg)=rnumber;
arg+=sizeof(long double);
break;
default:
return res;
}
break;
default:
break;
}
format++;
res++;
}
return res;
}