C实现日志等级控制

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <time.h>

#define SJXC_LOG_DEBUG(level, format, arg...)     SJXC_log_msg_print(level, __FILE__, __func__, __LINE__, format, ##arg)

#ifdef SJXC_DISABLE_DEBUG
#define SJXC_REAL_DEBUG_LEVEL    0
#else
#define SJXC_REAL_DEBUG_LEVEL    SJXC_DEBUG_LEVEL
#endif

#define SJXC_ERROR   (1 << 0)
#define SJXC_WARN    (1 << 1)
#define SJXC_INFO    (1 << 2)
#define SJXC_DEBUG   (1 << 3)

int SJXC_DEBUG_LEVEL = 1;

struct SJXC_gdb {
    int level;
    const char *msg;
};

struct SJXC_gdb SJXC_gdb_table[] = { 
    {SJXC_ERROR, "Config the log level as error."},
    {SJXC_WARN, "Config the log level as warn."},
    {SJXC_INFO, "Config the log level as info."},
    {SJXC_DEBUG, "Config the log level as DEBUG."}
};

void SJXC_print_debuf_usage(void)
{
    struct SJXC_gdb *p_gdb;
    fprintf(stderr, 
            "    To calculate the debug level, logically 'or'
"
            "    some of the following values together to get a bebug level:
");
    for (p_gdb = SJXC_gdb_table; p_gdb < SJXC_gdb_table + (sizeof(SJXC_gdb_table) / sizeof(struct SJXC_gdb)); p_gdb++) {
        fprintf(stderr, "	%d:	%s
", p_gdb->level, p_gdb->msg);
    }   
    fprintf(stderr, "
");
}

void SJXC_log_msg_print(int level, const char *file, const char *func, const int line, char *fmt, ...)
{   
    char *status;
    
    switch (level) {
        case SJXC_ERROR:
            status = "ERROR";
            break;
        case SJXC_WARN:
            status = "WRAN";
            break;
        case SJXC_INFO:
            status = "INFO";
            break;
        case SJXC_DEBUG:
            status = "DEBUG";
            break;
        default:
            printf("Debug message level ERROR!
");
    }
    
    if (SJXC_REAL_DEBUG_LEVEL & level) {
        char msg_buf[20*1024];
        char *ascii_time_buf;
        time_t tnow = time(NULL);
        va_list ap;
        
        ascii_time_buf = asctime(localtime(&tnow));
        ascii_time_buf[strlen(ascii_time_buf) - 1] = '';
        
        va_start(ap, fmt);
        sprintf(msg_buf, "    ------> [ %s %s:%s:%d ] %s ", ascii_time_buf, file, func, line, status);
        vsprintf(msg_buf + strlen(msg_buf), fmt, ap);
        fprintf(stderr, "%s
", msg_buf);
        va_end(ap);
    }
}

#if 1
int main(void)
{
    int i = 0;
    printf("%d
", SJXC_REAL_DEBUG_LEVEL);
    SJXC_print_debuf_usage();
    while( i != 32) {
        SJXC_log_msg_print(SJXC_ERROR, __FILE__, __func__, __LINE__, "1234567890");
        i++;
    }
　　return 0;
}
#endif