标签：blog http io ar 使用 sp java for 文件
实现可变长度将用到以下这些宏:
void va_start( va_list arg_ptr, prev_param );
type va_arg( va_list arg_ptr, type );
void va_end( va_list arg_ptr );
va在这里是variable-argument(可变参数)的意思.
这些宏定义在stdarg.h中,所以用到可变参数的程序应该包含这个头文件。
实现步骤如下：
/* Writen by samdy1990 at 1st December 2014
in SICT CNC lab
reference:http://www.cnhonkerarmy.com/blog-719-654.html
*/
#include <stdio.h>
#include <stdarg.h>//must include the head file.
#define FORMATLEN 100
int miniscanf(char * format,...)
{
va_list ap;
va_start(ap,format);// make ap point to 1st unnamed arg
int *ival;
unsigned *uval;
double *dval;
char *sval,*p
int i = 0;
char *localfmt[FORMATLEN];
//loop
for(p=format; *p;p++)//to read the format string.
{
if(*p != '%')
{
localfmt[i++] = *p;
continue;
}
else
{
localfmt[i++] = '%';
while(*(p+1)&&!isalpha(*(p+1)))
{
localfmt[i++] = *++p;
}
localfmt[i++] = *(p+1);
loaclfmt[i] = '\0';
switch (*++p)
{
case 'd':
case 'i':
ival = va_arg(ap,int *);
scanf(localfmt,ival);
break;
case 'x':
case 'X':
case 'o':
case 'u':
uval = va_arg(ap,unsigned *);
scanf(localfmt,uval);
break;
case 'g':
case 'e':
case 'f':
dval = va_arg(ap,double *);
scanf(localfmt,dval);
break;
case 's':
sval = va_arg(ap,char *);
scanf(localfmt,sval);
break;
default:
scanf(localfmt);
break;
}
i=0;
}
}
val_end(ap);
}标签：blog http io ar 使用 sp java for 文件
原文地址：http://blog.csdn.net/samdy1990/article/details/41647753
