log4c日志库在Linux中的使用

﹏ヽ暗。殇╰゛Y 2022-06-10 23:58 358阅读 0赞

1.简介  
 Log4c基本概念  
Log4c中有三个重要的概念, Category, Appender, Layout。

*  Category用于区分不同的Logger, 其实它就是个logger。在一个程序中我们可以通过Category来指定很多的Logger，用于不同的目的。

*  Appender用于描述输出流，通过为Category来指定一个Appender，可以决定将log信息来输出到什么地方去，比如stdout, stderr, 文件, 或者是socket等等

*  Layout用于指定日志信息的格式，通过为Appender来指定一个Layout,可以决定log信息以何种格式来输出，比如是否有带有时间戳， 是否包含文件位置信息等，以及他们在一条log信息中的输出格式的等。

2.下载log4c  
[log4c][] ：http://sourceforge.net/projects/log4c/  
  
3.安装  
我的操作系统是RHEL5，直接解压安装即可。  
\#tar xvzf log4c-1.2.1.tar.gz  
\#cd log4c-1.2.1  
\#./configure --prefix=/usr/local  
\#make  
\#make install

![log4c在Linux中的使用 - myswirl - 漩涡的窝][log4c_Linux_ - myswirl -]

安装成功会在/usr/local/lib下看到liblog4cplus.a，在/usr/local/include下有个liblog4cplus文件夹  
注意：将/usr/local/lib下的文件copy到/usr/lib.  
  
4.第一个例子  
  
 可从CSDN下载： [http://download.csdn.net/source/2629059][http_download.csdn.net_source_2629059]  ,或者直接copy下面代码。   
   
工程文件如下图所示：

![log4c在Linux中的使用 - myswirl - 漩涡的窝][log4c_Linux_ - myswirl - 1]

本工程共7个文件，源码如下：  
\----------------------------------------------------main.c---------------------------------------------------------------  
 \#include <stdio.h>  
\#include "mylog.h"  
\#include "other.h"  
  
int main(int argv, char \*\*argc) \{  
int i;  
if ( mylog\_init() == 1 )  
\{  
printf("mylog\_init() failed!\\n");  
\}  
  
for(i=0;i<140000;i++)  
\{  
LOG("%s%d","Hello!-",i);  
otherFunc();  
\}  
if(mylog\_fini() == 1)  
\{  
printf("mylog\_fini() failed!\\n");  
\}  
return 0;  
\}  
\----------------------------------------------------------------------------------------------------------------------------  
\---------------------------------------------------------Makefile-------------------------------------------------------  
 **TARGET=log4ctest  
OBJS=main.o other.o mylog.o  
INC=./  
LOG4CINC=/usr/local/include/log4c  
LIBPATH=./  
  
%.o:%.c  
g++ -c -I$(LOG4CINC) -I$(INC) $< -o $@  
  
%.o:%.cpp  
g++ -Wall -c -g -I$(INC) $< -o $@  
  
$(TARGET):$(OBJS)  
g++ $(OBJS) -llog4c -o $(TARGET)  
  
.PHONY:clean  
  
clean:  
rm \*.o $(TARGET)**   
\----------------------------------------------------------------------------------------------------------------------------  
\--------------------------------------------------------log4crc----------------------------------------------------------  
 <?xml version="1.0" encoding="ISO-8859-1"?>  
<!DOCTYPE log4c SYSTEM "">  
<log4c version="1.2.1">  
<config>  
<bufsize>0</bufsize>  
<debug level="2"/>  
<nocleanup>0</nocleanup>  
<reread>1</reread>  
</config>  
  
<category name="root" priority="notice"/>  
<category name="linuxany.com" priority="debug" appender="stderr" />  
<category name="log4ctest" priority="debug" appender="myrollingfileappender" />  
  
<rollingpolicy name="myrollingpolicy" type="sizewin" maxsize="104857600" maxnum="10" />  
  
<appender name="myrollingfileappender" type="rollingfile" logdir="./" prefix="mylogfile" layout="dated" rollingpolicy="myrollingpolicy" />  
<appender name="stdout" type="stream" layout="basic"/>  
<appender name="stderr" type="stream" layout="dated"/>  
<appender name="syslog" type="syslog" layout="basic"/>  
<appender name="s13file" type="s13\_file" layout="basic"/>  
<appender name="plain\_stderr" type="s13\_stderr" layout="none"/>  
<appender name="cat\_stderr" type="s13\_stderr" layout="catlayout"/>  
<appender name="xml\_stderr" type="s13\_stderr" layout="xmllayout"/>  
<appender name="user\_stderr" type="s13\_stderr" layout="userlayout"/>  
  
<layout name="basic" type="basic"/>  
<layout name="dated" type="dated"/>  
<layout name="catlayout" type="s13\_cat"/>  
<layout name="xmllayout" type="s13\_xml"/>  
<layout name="none" type="s13\_none"/>  
<layout name="userlayout" type="s13\_userloc"/>  
  
</log4c>  
\----------------------------------------------------------------------------------------------------------------------------  
  
\-----------------------------------------------------------other.h-------------------------------------------------------  
   
void otherFunc(void);   
\----------------------------------------------------------------------------------------------------------------------------  
  
\-------------------------------------------------------------other.c------------------------------------------------------  
 \#include "mylog.h"  
\#include "other.h"  
  
void otherFunc(void)  
\{  
LOG("%s","Enter");  
\}   
\-----------------------------------------------------------------------------------------------------------------------------  
  
\-------------------------------------------------------------mylog.h-----------------------------------------------------  
 \#ifndef \_MYLOG\_H\_  
\#define \_MYLOG\_H\_  
  
\#include <string.h>  
\#include <stdlib.h>  
  
\#ifdef \_\_cplusplus  
extern "C"  
\{  
\#endif  
  
\#include "log4c.h"  
  
\#ifdef \_\_cplusplus  
\}  
\#endif  
  
\#define MYLOG\_CATEGORY\_NAME "log4ctest"  
\#define MYLOG\_PRIORITY LOG4C\_PRIORITY\_WARN  
  
//1.LOG4C\_PRIORITY\_ERROR  
//2.LOG4C\_PRIORITY\_WARN  
//3.LOG4C\_PRIORITY\_NOTICE  
//4.LOG4C\_PRIORITY\_DEBUG  
//5.LOG4C\_PRIORITY\_TRACE  
  
extern int mylog\_init();  
extern void log\_message(char\* file, int line, const char\* func,const char\* a\_format, ...);  
extern int mylog\_fini();  
\#define LOG(fmt,args...) log\_message(\_\_FILE\_\_, \_\_LINE\_\_, \_\_FUNCTION\_\_,fmt ,\#\# args);  
\#endif   
  
\-----------------------------------------------------------------------------------------------------------------------------  
  
\-------------------------------------------------------------mylog.c-----------------------------------------------------  
  
 \#include "mylog.h"  
  
const char \*format = "\[%10s\]\[%4d\]\[%10s()\]: ";  
  
log4c\_category\_t\* mycat = NULL;  
  
int mylog\_init()  
\{  
if (log4c\_init() == 1)  
\{  
return 1;  
\}  
mycat = log4c\_category\_get(MYLOG\_CATEGORY\_NAME);  
return 0 ;  
\}  
  
void log\_message(char\* file, int line, const char\* func,const char\* a\_format, ...)  
\{  
char \*file\_info;  
char \*new\_format;  
size\_t info\_len;  
size\_t new\_format\_len;  
va\_list va;  
  
info\_len = strlen(format) + 50;  
file\_info = (char \*) malloc(info\_len);  
sprintf(file\_info, format,file, line,func );  
  
new\_format\_len = strlen(file\_info) + strlen(a\_format) + 2;  
new\_format = (char \*) malloc(new\_format\_len);  
sprintf(new\_format, "%s%s", file\_info, a\_format);  
  
va\_start(va, a\_format);  
log4c\_category\_vlog(mycat, MYLOG\_PRIORITY, new\_format, va);  
va\_end(va);  
  
free(file\_info);  
free(new\_format);  
\}  
  
int mylog\_fini()  
\{  
return(log4c\_fini());  
\}   
  
\-----------------------------------------------------------------------------------------------------------------------------  
  
编译、运行结果如下图所示：

![log4c在Linux中的使用 - myswirl - 漩涡的窝][log4c_Linux_ - myswirl - 2]

日志文件：mylogfile.0

![log4c在Linux中的使用 - myswirl - 漩涡的窝][log4c_Linux_ - myswirl - 3]

[log4c]: http://sourceforge.net/projects/log4c/
[log4c_Linux_ - myswirl -]: http://img308.ph.126.net/MaagPSFVBMlj5MbXwPbIvQ==/3914191026138619816.png
[http_download.csdn.net_source_2629059]: http://download.csdn.net/source/2629059
[log4c_Linux_ - myswirl - 1]: http://img.ph.126.net/or4f6Ow_qj8FurkV1rh1sQ==/3263702354961442030.png
[log4c_Linux_ - myswirl - 2]: http://img306.ph.126.net/fLFlXhCZcYGxQ_C-v7ogFA==/3869436504841629913.png
[log4c_Linux_ - myswirl - 3]: http://img314.ph.126.net/iKsgftLGBAvBpYwrajg9dQ==/3891954502978480850.png