sprintf()的snprintf()用法

注意利用返回值（字符串长度）

CODE:

#include <stdio.h>
using namespace std;
int main()
{
char buf[100];
sprintf(buf, "%.*s", 4, "fluke");
printf("%s\n", buf);
memset(buf, 0, sizeof(buf));
snprintf(buf, 3, "%s", "fluke");
printf("%s\n", buf);
return 0;
}两种用法看看输出就明白了：

QUOTE:

fluk
flu

snprintf(_snprintf)的声明是这样的

int _snprintf(
   char *buffer,
   size_t count,
   const char *format [,
      argument] ...
);

If len < count, then len characters are stored in buffer, a null-terminator is appended, and len is returned.

If len = count, then len characters are stored in buffer, no null-terminator is appended, and len is returned.

If len > count, then count characters are stored in buffer, no null-terminator is appended, and a negative value is returned.

char sa[256]={0};
int result = _snprintf(sa,sizeof(sa),"%s",sb);
if(result==sizeof(sa) || result<0)
{
    printf("warning:sting will be truncated");
   sa[sizeof(sa)-1]=0;
}