Linux 打印可变参数日志

实现了传输进去的字符串所在的文档，函数和行数显示功能。

实现了将传入的可变参数打印到日志功能。

1#include<stdio.h>
2#include<stdarg.h>
3#include<string.h>
4
5const char * g_path = "/home/exbot/wangqinghe/log.txt";
6#define LOG(fmt,...) my_fprintf(__FILE__,__FUNCTION__,__LINE__,fmt,##__VA_ARGS__)
7
8int my_fprintf(const char *pFileName,const char *pFunName,const long lLine,const char* fmt,...)
9{
10    printf("%s-%s-%d\n",__FILE__,__FUNCTION__,__LINE__);
11    int iRet = -1;
12    int i = 0;
13    va_list args;
14    va_start(args,fmt);
15    FILE* fp = NULL;
16    fp = fopen(g_path,"at+");
17
18    int nFileNameLen = strlen(pFileName);
19    char szLine[10] = {0};
20    sprintf(szLine,"%ld",lLine);
21    int nLineLen = strlen(szLine);
22    int nSpaceLen = 30 - nFileNameLen - nLineLen;
23    for(i = 0;  i < nSpaceLen; ++i)
24    {
25        fwrite(" ",1,1,fp);
26    }
27    fprintf(fp,"%s:%ld ",pFileName,lLine);
28    iRet = vfprintf(fp,fmt,args);
29    printf("iRet = %d\n",iRet);
30    va_end(args);
31    fflush(fp);    
32    fclose(fp);
33    return iRet;
34}
35
36
37int main()
38{
39    char *p = "this is my first debug";
40    printf("%s-%s-%d\n",__FILE__,__func__,__LINE__);
41    LOG("%s %d\n",p,1);
42    return 0;
43}    

输出结果：

exbot@ubuntu:~/wangqinghe/C/20190703$ gcc log.c -o log

exbot@ubuntu:~/wangqinghe/C/20190703$ ./log

log.c-main-41

log.c-my_fprintf-10

iRet = 25

在/home/exbot/wangqinghe/log.txt中有如下输出结果：

简单化版：

1#include<stdio.h>
2#include<stdarg.h>
3#include<string.h>
4
5const char * g_path = "/home/exbot/wangqinghe/log.txt";
6#define LOG(fmt,...) my_fprintf(__FILE__,__FUNCTION__,__LINE__,fmt,##__VA_ARGS__)
7
8int my_fprintf(const char *pFileName,const char *pFunName,const long lLine,const char* fmt,...)
9{
10    printf("%s-%s-%d\n",__FILE__,__FUNCTION__,__LINE__);
11    int iRet = -1;
12    int i = 0;
13    va_list args;
14    va_start(args,fmt);
15    FILE* fp = NULL;
16    fp = fopen(g_path,"at+");
17    fprintf(fp,"%s:%ld ",pFileName,lLine);
18    iRet = vfprintf(fp,fmt,args); //使用参数列表发送格式化输出到流stream中
19    printf("iRet = %d\n",iRet);
20    va_end(args);
21    fflush(fp);    
22    fclose(fp);
23    return iRet;
24}
25
26
27int main()
28{
29    char *p = "this is my first debug";
30    printf("%s-%s-%d\n",__FILE__,__func__,__LINE__);
31    LOG("%s %d\n",p,1);
32    //getchar();
33    return 0;
34}    

输出结果：