C语言调试手段:锁定错误的实现方法

printf("line : %d\n", __LINE__);                   //当前行数
printf("filename : %s\n", __FILE__);             //当前文件名
printf("function : %s\n", __FUNCTION__);  //当前函数
printf("time : %s\n", __TIME__);                  //当前时间
printf ("date : %s\n",  __DATE__);              //当前日期
输出：
line : 10
filename : test.c
function : main.c
time : 14:13:51
date : Oct 13 2012

[root@localhost for_test]# cat erroutput.c
#include <stdio.h>
#include <assert.h>
#define _DEBUG(msg...)    printf("[ %s,%s, %d ]=>",__FILE__, __FUNCTION__, __LINE__);  printf(msg);printf("\r\n")
#define _ERROR(msg...)    printf("[ error: %s, %d]=>", __FILE__,  __LINE__);printf(msg); printf("\r\n")
#define _ASSERT(exp)      \
                        do {\
                                if (!(exp)) {\
                                printf( "[ %s ]  ",#exp);printf("\r\n");\
                                assert(exp);\
                                }\
                        } while (0)
int main(void)
{
        char *p = NULL;
        _DEBUG("DEBUG!");
        _ERROR("ERROR!");
        _ASSERT(NULL != p);
        return 0;
}

[root@localhost for_test]# gcc erroutput.c
[root@localhost for_test]# ./a.out
[ erroutput.c,main, 17 ]=>DEBUG!
[ error: erroutput.c, 18]=>ERROR!
[ NULL != p ]
a.out: erroutput.c:19: main: Assertion `((void *)0) != p' failed.
已放弃

#ifdef DEBUG
    #define DBG(fmt, args...)  printf("Debug " fmt, ##args)// ##运算符用于把参数连接到一起。预处理程序把出现在##两侧的参数合并成一个符号。
#else
    #define DBG(fmt, args...)
#endif
#define ERR(fmt, args...)  printf("Error " fmt, ##args)
[root@localhost for_test]# cat debug_err.c
#include <stdio.h>
//#define DEBUG
int main(void)
{
       DBG("xxxx\n");
       ERR("xxxx\n");
       return 0;
}
[root@localhost for_test]# ./a.out
Error xxxx

#ifdef __DEBUG
    #define DBG(fmt, args...) fprintf(stderr,"Encode Debug: " fmt, ## args)
#else
    #define DBG(fmt, args...)
#endif
#define ERR(fmt, args...) fprintf(stderr,"Encode Error: " fmt, ## args)