如何克服SSCANF中的缺点 [英] how to overcome cons in SSCANF

问题描述

如何用sscanf解析一个空的子字符串…….
如果我的字符串str [] =是第一，第三，最后.如果我的第二个子字符串为零，我将无法读取第三个也是最后一个子字符串.是否有解决此错误的解决方案..... ?????


代码:

Hi, how to parse a empty substring with sscanf.......
if my string str[]="is first,,third,final." i cannot able to read the third and final substring if my second substring is zero. Is there an solution to overcome this error.....?????


Code:

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

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

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

对于这个程序，如果我执行我的输出是

for this program if i execute my output is

>first
>second
>25.5
>15

但是，如果我尝试删除令牌字符串指针中的子字符串"second" ...并且如果我尝试执行，则输出为:

but if i try to remove the substring "second" in the tokenstring pointer... and if i try to execute, then i get output as:

char *tokenstring = "first,,25.5,15";

>first
>(blank)
>0.00
>0 

如何阅读字符串"tokenstring"中的第三和第四子字符串...任何建议??????????

how do i read the third and fourth substring in the string"tokenstring"...any suggestions ??????????

推荐答案

sscanf功能(例如，参见此处) [竞争对手" [ ^ ]).

sscanf function (see, for instance here[^]) does NOT take regular expressions in the format string.
You may either:

• Use a library for regular expression parsing (see, for instance, ''The Competitors''[^]).

• 解析您自己的输入字符串(出于此目的，您可能会明智地使用strtok，请参见 strtok文档 [ ^ ]). li>

• Parse yourself the input string (you may wisely use, strtok for the purpose, see strtok documentation[^]).

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