【25】用户态下分级别打印日志和把日志打印进文件

小鱼儿 2022-01-11 03:13 215阅读 0赞

linux kernel内核可以按日志级别打印，但是用户态下没有这种接口，这样调试的日志需要在release版本删除，以后再想调试又要加回来比较麻烦。写了一个用户态的按级别打印的小demo，仅供娱乐。  
PS:比较懒，其实mian函数之上，放到.h文件更好一下，这样其他函数直接包含该头文件就可以使用了。如果想要改变打印出来的module的name 只要在自己app的头文件的\#define MODULENAME “moduleA” 就可以把pcieteset的打印改成moduleA了

#include <stdio.h>
    #include <string.h>
    
    #ifndef MODULENAME
    #define MODULENAME "pcieteset"
    #endif
    
    /* log level,
     * if default_level is LOG_DISABLE, no log is allowed output,
     * if default_level is LOG_ERR, only ERR is allowed output,
     * if default_level is LOG_WARNING, only ERR and WARNING is allowed output,
     * if default_level is LOG_INFO, ERR/WARNING and INFO are allowed output,
     * if default_level is LOG_DEBUG, all log are allowed output*/
    
    enum log_level {
        LOG_DISABLE = 0,
        LOG_ERR = 1,
    	LOG_WARNING = 2,
        LOG_INFO = 3,
        LOG_DEBUG = 4,
        LOG_BUTT = 5,
    };
    
    /* the macro to set debug level, you should call it 
     * once in the files you need use debug system*/
    static enum log_level default_level = LOG_BUTT;
    #define SET_DEFAULT_LEVEL(level)  (default_level = level)
    /*print log on console*/
    #define CONSOLE_PERR(format, ...)						\
    do {													\
    	if (default_level >= LOG_ERR)						\
    	{													\
    		printf( "[%s File:%s, Func:%s, Line:%d] [\033[31mERR\033[0m]: "format".\n", MODULENAME, __FILE__, __FUNCTION__, __LINE__, ##__VA_ARGS__);	\
    	}													\
    } while (0)
    
    #define CONSOLE_PWARN(format, ...)						\
    do {													\
    	if (default_level >= LOG_WARNING)					\
    	{													\
    		printf( "[%s File:%s, Func:%s, Line:%d] [\033[31mWARN\033[0m]: "format".\n", MODULENAME, __FILE__, __FUNCTION__, __LINE__, ##__VA_ARGS__);	\
    	}													\
    } while (0)
    
    #define CONSOLE_PINFO(format, ...)						\
    do {													\
    	if (default_level >= LOG_INFO)						\
    	{													\
    		printf( "[%s File:%s, Func:%s, Line:%d] [\033[31mINFO\033[0m]: "format".\n", MODULENAME, __FILE__, __FUNCTION__, __LINE__, ##__VA_ARGS__);	\
    	}													\
    } while (0)
    
    #define CONSOLE_PDBG(format, ...)						\
    do {													\
    	if (default_level >= LOG_DEBUG)						\
    	{													\
    		printf( "[%s File:%s, Func:%s, Line:%d] [\033[31mDBG\033[0m]: "format".\n", MODULENAME, __FILE__, __FUNCTION__, __LINE__, ##__VA_ARGS__);	\
    	}													\
    } while (0)
    
    /*save log to file*/
    #define LOG_FILE "/tmp/"
    #define LOG_BUFFER_MAX (4096)
    #define LOG2FILE(format, ...)							\
    {														\
    	char buffer[LOG_BUFFER_MAX+1]={0};					\
    	char filename[LOG_BUFFER_MAX+1]={0};				\
    	snprintf(filename, LOG_BUFFER_MAX, "%s%s",LOG_FILE, MODULENAME);	\
    	snprintf( buffer, LOG_BUFFER_MAX, "[%s File:%s, Func:%s, Line:%d]: "format"}\n", MODULENAME, __FILE__,__FUNCTION__, __LINE__,##__VA_ARGS__);	\
    	FILE* fd = fopen(filename, "a");					\
    	if ( fd != NULL )									\
    	{													\
    		fwrite( buffer, strlen(buffer), 1, fd );		\
    		fflush( fd );									\
    		fclose( fd );									\
    	}													\
    }
    
    int main ()
    {
    	int data = 999;
    	int data2 = 666;
    	SET_DEFAULT_LEVEL(LOG_INFO);
        CONSOLE_PERR( "11data = %d data2 = %d", data ,data2);
    	CONSOLE_PWARN( "22data = %d data2 = %d", data ,data2);
    	CONSOLE_PINFO( "33data = %d data2 = %d", data ,data2);	
    	CONSOLE_PDBG( "44data = %d data2 = %d", data ,data2);
    	LOG2FILE("data = %d ata2 = %d", data ,data2);
        return 0;
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpbmppYXNlbg_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpbmppYXNlbg_size_16_color_FFFFFF_t_70]: /images/20220111/daee47d5c8384c8c972628c655c745a4.png