一、sscanf示例

/* The following sample illustrates the use of brackets and the
   caret (^) with sscanf().
   Compile options needed: none
*/ 

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

char *tokenstring = "first,25.5,second,15";
int result, i, rv;
double fp;
char o[10], f[10], s[10], t[10];

void main()
{
   result = sscanf(tokenstring, "%[^','],%[^','],%[^','],%s", o, s, t, f);
   fp = atof(s);
   i  = atoi(f);
   printf("%s/n %lf/n %s/n %d/n", o, fp, t, i);
}

二、fscanf示例

/* The following sample illustrates the use of brackets and the
   caret (^) with sscanf().
   Compile options needed: none
*/ 

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

char *tokenstring = "first,25.5,second,15";
int result, i;
double fp;
char o[10], f[10], s[10], t[10];

FILE *filep; //檔案的開啟、關閉操作在此省略

void main()
{
   rv = fscanf(filep, "%s", tokenstring);

   result = sscanf(tokenstring, "%[^','],%[^','],%[^','],%s", o, s, t, f);

   fp = atof(s);
   i  = atoi(f);
   printf("%s/n %lf/n %s/n %d/n", o, fp, t, i);

}
如果你直接使用fscanf讀取檔案中存放的字串"first,25.5,second,15"，
即fscanf(fp, "%[^','],%[^','],%[^','],%s", o, s, t, f);
結果會失敗，原因我還沒有調查出來。

你必須先把檔案中存放的字串讀入tokenstring中，將檔案操作轉化為記憶體操作，才能解析成功。