从文件到C中的结构 [英] From file to structure in C

问题描述

我试图从文件写入到C中的结构中。每当我尝试在结构中赋值时，会给出错误：赋值中的不兼容类型。

我的结构看起来像这样：

  struct competition {
 char eventTitle [79]; 
 char date [79]; 
 char time [79]; 
}; 
  

基本上我想打开文件并在结构中分配不同的值。即。第一行在文件 - > eventTitle，第二行 - >日期，第三行 - >时间。

以下是我如何分配它：

  FILE * naDaSt; 
 char * mode =r; 
 int lines = 0; 
 char line [79]，current [79]; 
 
 
 naDaSt = fopen（nameDateStart，mode）; 
 if（naDaSt == NULL）{
 printf（Can not find the files。）; 
 exit（1）; 
} else {
 struct competition comp，* p; 
 p =& comp; 
 while（fgets（line，79，naDaSt））{
 lines ++; 
 if（lines == 1）{
 p-> eventTitle = line; 
} 
 if（lines == 2）{
 p-> date = line; 
} 
 if（lines == 3）{
 p-> time = line; 
 
 
 
 code $ pre 
 $ b 
} 
 
 
 
任何人都可以帮助我吗？根本原因： 
 
 
 
 
 
解决方案您不能这样做： 
 
 
  p-> eventTitle = line; 
 p-> date = line; 
 p-> time = line; 
  
您正尝试使用不能完成的赋值来分配数组，数组需要被复制。编译器正确地报告错误：
 
 pre $ 错误：赋值中的不兼容类型
  

因为确实类型你试图 assign 是不兼容的。

解决方案：

您需要使用 strcpy ，然后复制字符数组并将其分配。

I am trying to write from file to structure in C. Whenever I try to assign value in structure it gives me error: incompatible types in assignment.

My structure looks like this:

struct competition{
char eventTitle[79];
char date[79];
char time[79];
};

Basically I want to open the file and assign individual line to different value in structure. ie. first line in file -> eventTitle, second line -> date, third line -> time.

Here is how I try to assign it:

FILE *naDaSt;
char *mode = "r";
int lines = 0;
char line[79], current[79];


naDaSt = fopen(nameDateStart, mode);
if(naDaSt == NULL){
    printf("Can't find the files.");
    exit(1);
}else{
    struct competition comp, *p;
    p = ∁
    while(fgets(line, 79, naDaSt)){
        lines++;
        if(lines == 1){
            p->eventTitle= line;
        }
        if(lines == 2){
            p->date = line;
        }
        if(lines == 3){
            p->time = line;
        }
    }
}    

}

Could anyone help me?

解决方案

Root Cause:

You cannot do this:

        p->eventTitle = line;
        p->date = line;
        p->time = line;

You are trying to assign arrays using assignment which cannot be done, arrays need to be copied. The compiler rightly reports the error:

error: incompatible types in assignment

because indeed the type you are trying to assign are incompatible.

Solution:

Instead, You need to use strcpy and copy the character arrays and not assign them.

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