Question

struct proc_time /* info and times about a single process*/ 
{ 
    pid_t pid; /* pid of the process*/ 
    char name[16]; /* file name of the program executed*/ 
    unsigned long start_time; /* start time of the process*/ 
    unsigned long real_time; /* real time of the process execution*/ 
    unsigned long user_time; /* user time of the process*/ 
    unsigned long sys_time; /* system time of the process*/ 
}; 

struct proctimes /* info and times about all processes we need*/ 
{ 
    struct proc_time proc; /* process with given pid or current process */ 
    struct proc_time parent_proc; /* parent process*/ 
    struct proc_time oldest_child_proc; /* oldest child process*/ 
    struct proc_time oldest_sibling_proc; /* oldest sibling process*/ 
};

我无法理解我的声明出了什么问题，我在第二个struct开始的行中遇到以下错误：

期望';'，标识符或'（'''''''''''''。

Answer 1

问题是您使用/.../作为注释分隔符是非法的。这一行：

struct proc_time proc; /process with given pid or current process/

应替换为：

 struct proc_time proc; /* process with given pid or current process */

Answer 2

如果您在文件范围中声明这些结构（假设您修复了注释问题），则没有真正的原因。

但是，如果你以某种方式设法在更大的结构中声明这些结构，那么你确实会从C编译器中得到一个错误

struct some_struct
{

  struct proc_time
  { 
    ...
  }; /* <- error: identifier expected */

  struct proctimes
  { 
    ...
  }; /* <- error: identifier expected */

};

在C语言中，以“嵌套”方式声明结构类型而不立即声明该类型的数据字段是非法的。

Answer 3

在分号之前和结束花括号之后添加结构别名，允许我编译结构（在添加main方法并包含stdlib.h之后使用gcc）。

struct proc_time /* info and times about a single process*/ 
{ 
    pid_t pid; /* pid of the process*/ 
    char name[16]; /* file name of the program executed*/ 
    unsigned long start_time; /* start time of the process*/ 
    unsigned long real_time; /* real time of the process execution*/ 
    unsigned long user_time; /* user time of the process*/ 
    unsigned long sys_time; /* system time of the process*/ 
} proc_time; 

struct proctimes /* info and times about all processes we need*/ 
{ 
    struct proc_time proc; /* process with given pid or current process */ 
    struct proc_time parent_proc; /* parent process*/ 
    struct proc_time oldest_child_proc; /* oldest child process*/ 
    struct proc_time oldest_sibling_proc; /* oldest sibling process*/ 
} proctimes;

错误：预期';'，标识符或'''在'struct'之前

3 个答案: