问题描述
我需要读取一个 .csv 文件。然后我需要放置“值”结构数组，但是当我放置整数变量时，我得到了这个 "expected ‘char * restrict’ but argument is of type ‘int’" error。
这是我的代码：
#include <stdio.h>
#include <string.h>
#define DATA_FILE "students.csv"
typedef struct record {
int id;
int grade;
char name[15];
char surname[15];
char email[26];
}dict;
int main()
{
FILE *fp;
struct record Myrecord;
fp=fopen("students.csv","r");
if(!fp){
printf("Error occured");
return 0;
}
char buff[102400];
int row_count=0;
int field_count=0;
dict values[99900];
int i=0;
while(fgets(buff,102400,fp))
{
field_count=0;
row_count++;
if(row_count == 1){
continue;
}
char *field=strtok(buff,";");
while (field)
{
if(field_count==0){
strcpy(values[i].id,field);
}
if(field_count==1){
strcpy(values[i].name,field);
}
if(field_count==2){
strcpy(values[i].surname,field);
}
if(field_count==3){
strcpy(values[i].email,field);
}
if(field_count==4){
strcpy(values[i].grade,field);
}
printf("%s ",field);
field=strtok(NULL,";");
field_count++;
}
i++;
}
return 0;
}
这是我得到的错误：
week3.c: In function ‘main’:
week3.c:44:30: warning: passing argument 1 of ‘strcpy’ makes pointer from integer without a cast [-Wint-conversion]
strcpy(values[i].id,field);
~~~~~~~~~^~~
In file included from week3.c:2:
/usr/include/string.h:121:14: note: expected ‘char * restrict’ but argument is of type ‘int’
extern char *strcpy (char *__restrict __dest,const char *__restrict __src)
^~~~~~
week3.c:56:18: warning: passing argument 1 of ‘strcpy’ makes pointer from integer without a cast [-Wint-conversion]
strcpy(values[i].grade,field);
~~~~~~~~~^~~~~~
In file included from week3.c:2:
/usr/include/string.h:121:14: note: expected ‘char * restrict’ but argument is of type ‘int’
extern char *strcpy (char *__restrict __dest,const char *__restrict __src)
^~~~~~
Segmentation fault
[Done] exited with code=139 in 0.174 seconds
解决方法
查看错误消息。 strcpy 接受两个 char * 参数，但在 strcpy(values[i].id,field) 中，values[i].id 为 int。
strcpy 的原型包含在编译器输出中：
extern char *strcpy (char *__restrict __dest,const char *__restrict __src)
week3.c:44:30: warning: passing argument 1 of ‘strcpy’ makes
pointer from integer without a cast [-Wint-conversion]
strcpy(values[i].id,field);
~~~~~~~~~^~~
id 是一个整数，field 是一个字符串——你不能将一个字符串复制到一个整数——你必须_解释 _ 字符串：
values[i].id = (int)strtol( field,NULL,0 ) ;
尽管很可能 id 在任何情况下都应该是一个字符串，即使它只包含数字 - 毕竟它不是您要对其执行算术的对象。
In file included from week3.c:2: /usr/include/string.h:121:14: note:
expected ‘char * restrict’ but argument is of type ‘int’ extern char
*strcpy (char *__restrict __dest,const char *__restrict __src)
^~~~~~
只是前一个错误的结果。始终从头开始阅读和修复错误，如果消息看起来像是上一期的“运行”，则重新编译。
week3.c:56:18: warning: passing argument 1 of ‘strcpy’ makes pointer
from integer without a cast [-Wint-conversion]
strcpy(values[i].grade,field);
~~~~~~~~~^~~~~~ In file included from week3.c:2: /usr/include/string.h:121:14: note: expected ‘char * restrict’ but
argument is of type ‘int’ extern char *strcpy (char *__restrict
__dest,const char *__restrict __src)
^~~~~~
同上。
values[i].grade = (int)strtol( field,0 ) ;
虽然在这里很清楚，grade 是一个整数是有道理的。
Segmentation fault
您运行损坏的代码是因为它们是警告而不是错误。所有编译器都有将警告视为错误的开关（警告通常是语义错误而不是语法错误 - 即编译器可以生成代码，但代码不太可能符合您的意图），您应该使用该开关（ -Werror 在 GCC 和 Clang 中，\WX 在 Microsoft 的编译器中）。有错误的代码不会运行，因为它不会编译 - 因此将警告转化为错误可以防止您运行语义损坏的代码。