Windows Linux可兼容版变长参数的实例程序

自己写的一个可变长参数的例子程序。

采用了Linux Windows可兼容版本函数。

main.c

1. /*
   
2.  * This project is implemented for testing variable-argument
   
3.  */
   
4. #include <stdio.h>
   
5. #include <stdlib.h>
   
6. 
   
7. #include "log.h"
   
8. 
   
9. FILE *fp_log = NULL;
   
10. 
    
11. void main(char arg, char *argv[])
    
12. {
    
13.   if ((fp_log = fopen("test.log", "w+")) == NULL)
    
14.   {
    
15.     printf("The file 'test.log' was not opened\n");
    
16.   }
    
17. 
    
18.   tc_log(fp_log, "%s", __FUNCTION__);
    
19.   tc_log(fp_log, "%s, %d", __FUNCTION__, 1);
    
20.   tc_log(fp_log, "%s, %d, %s, %d", __FUNCTION__, 2, __FUNCTION__, 2);
    
21. 
    
22.   if( fclose(fp_log))
    
23.     printf( "The file 'test.log' was not closed\n");
    
24. }

log.h

1. /*
   
2.  * File: log.h
   
3.  */
   
4. 
   
5. #ifndef __LOG_H__
   
6. #define __LOG_H__
   
7. #include <stdarg.h>
   
8. 
   
9. typedef char * va_list;
   
10. extern FILE *fp_log;
    
11. 
    
12. void tc_log(const FILE *fp_log, const char *fmt, ...);
    
13. void tc_log_default(const FILE *fp_log, const char * fmt, va_list vl);
    
14. #endif

log.c

1. /*
   
2.  * File: log.c
   
3.  */
   
4. #include "stdio.h"
   
5. #include "log.h"
   
6. 
   
7. 
   
8. void tc_log(const FILE *fp_log, const char *fmt, ...)
   
9. {
   
10.   va_list vl;
    
11. 
    
12.   /* Macro to set 'vl' to beginning of list of optional arguments */
    
13.   va_start(vl, fmt);
    
14.   
    
15.   tc_log_default(fp_log, fmt, vl);
    
16.   
    
17.   /* Macro to reset arg_ptr */
    
18.   va_end(vl);
    
19. 
    
20.   return;
    
21. }
    
22. 
    
23. void tc_log_default(const FILE *fp_log, const char * fmt, va_list vl)
    
24. {
    
25.   char line[1024];
    
26.   line[0] = 0;
    
27.   printf("strlen = %d, sizeof = %d\n", strlen(line), sizeof(line));
    
28. 
    
29.   vsnprintf(line + strlen(line), sizeof(line) - strlen(line), fmt, vl);
    
30.   fprintf(fp_log, "%s\n", line);
    
31. 
    
32.   return;
    
33. }