缺头文件的报错汇总

1,warning incompatible implicit declaration of built-in function ‘exit’

纠错：

确认调用exit函数的文件引用了头文件 #include

notic;_Exit,exit为

      _exit为

2，'system' was not declared in this scope

纠错：确认调用System的头文件#include

notice:pause在unix不能用？？

 

#include <stdio.h>
#include <stdlib.h>
#define TOK_ADD 5
#define MAXLINE 1
void do_line(char *);
void cmd_add(void);
int get_token(void);
int main(void)
{
        char line[MAXLINE];
        printf("MAXLINE=%d\n",MAXLINE);
        while (fgets(line,MAXLINE,stdin) != NULL)
                do_line(line);
        exit(0);
}

char *tok_ptr;
void do_line(char *ptr)
{
        int cmd;
        tok_ptr=ptr;
        while((cmd=get_token())>0)
        {
                /*switch(cmd)
                {
                case TOK_ADD:
                        cmd_add();
                        break;
                }*/
        }
}
/*void cmd_add(void)
{
        int token;
        token=get_token();
        printf("hello cmd_token\n");
}*/
int get_token(void)
{
        /*printf("get_token run\n");
        return 5;*/
}