Linux 打印可變參數日志

實現了傳輸進去的字符串所在的文檔，函數和行數顯示功能。

實現了將傳入的可變參數打印到日志功能。

#include<stdio.h>
#include<stdarg.h>
#include<string.h>const char * g_path = "/home/exbot/wangqinghe/log.txt";
#define LOG(fmt,...) my_fprintf(__FILE__,__FUNCTION__,__LINE__,fmt,##__VA_ARGS__)int my_fprintf(const char *pFileName,const char *pFunName,const long lLine,const char* fmt,...)
{printf("%s-%s-%d\n",__FILE__,__FUNCTION__,__LINE__);int iRet = -1;int i = 0;va_list args;va_start(args,fmt);FILE* fp = NULL;fp = fopen(g_path,"at+");int nFileNameLen = strlen(pFileName);char szLine[10] = {0};sprintf(szLine,"%ld",lLine);int nLineLen = strlen(szLine);int nSpaceLen = 30 - nFileNameLen - nLineLen;for(i = 0;  i < nSpaceLen; ++i){fwrite(" ",1,1,fp);}fprintf(fp,"%s:%ld ",pFileName,lLine);iRet = vfprintf(fp,fmt,args);printf("iRet = %d\n",iRet);va_end(args);fflush(fp);    fclose(fp);return iRet;
}int main()
{char *p = "this is my first debug";printf("%s-%s-%d\n",__FILE__,__func__,__LINE__);LOG("%s %d\n",p,1);return 0;
}    

輸出結果：

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中有如下輸出結果：

簡單化版：

#include<stdio.h>
#include<stdarg.h>
#include<string.h>const char * g_path = "/home/exbot/wangqinghe/log.txt";
#define LOG(fmt,...) my_fprintf(__FILE__,__FUNCTION__,__LINE__,fmt,##__VA_ARGS__)int my_fprintf(const char *pFileName,const char *pFunName,const long lLine,const char* fmt,...)
{printf("%s-%s-%d\n",__FILE__,__FUNCTION__,__LINE__);int iRet = -1;int i = 0;va_list args;va_start(args,fmt);FILE* fp = NULL;fp = fopen(g_path,"at+");fprintf(fp,"%s:%ld ",pFileName,lLine);iRet = vfprintf(fp,fmt,args); //使用參數列表發送格式化輸出到流stream中printf("iRet = %d\n",iRet);va_end(args);fflush(fp);    fclose(fp);return iRet;
}int main()
{char *p = "this is my first debug";printf("%s-%s-%d\n",__FILE__,__func__,__LINE__);LOG("%s %d\n",p,1);//getchar();return 0;
}    

輸出結果：

?