判断文件大小

feeling

1. 
   
2. #include <sys\stat.h>;
   
3. #include <stdio.h>;
   
4. #include <time.h>;
   
5. 
   
6. #define FILENAME "TEST.$$$"
   
7. 
   
8. int main(void)
   
9. {
   
10.    struct stat statbuf;
    
11.    FILE *stream;
    
12. 
    
13.    /* open a file for update */
    
14.    if ((stream = fopen(FILENAME, "w+")) == NULL)
    
15.    {
    
16.       fprintf(stderr, "Cannot open output file.\n");
    
17.       return(1);
    
18.    }
    
19. 
    
20.    /* get information about the file */
    
21.    stat(FILENAME, &statbuf);
    
22. 
    
23.    fclose(stream);
    
24. 
    
25.    /* display the information returned */
    
26.    if (statbuf.st_mode & S_IFCHR)
    
27. 
    
28.       printf("Handle refers to a device.\n");
    
29.    if (statbuf.st_mode & S_IFREG)
    
30.       printf("Handle refers to an ordinary file.\n");
    
31.    if (statbuf.st_mode & S_IREAD)
    
32.       printf("User has read permission on file.\n");
    
33.    if (statbuf.st_mode & S_IWRITE)
    
34.       printf("User has write permission on file.\n");
    
35. 
    
36.    printf("Drive letter of file: %c\n", 'A'+statbuf.st_dev);
    
37.    printf("Size of file in bytes: %ld\n", statbuf.st_size);
    
38.    printf("Time file last opened: %s\n", ctime(&statbuf.st_ctime));
    
39. 
    
40.    return 0;
    
41. }
    

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feeling

当然，fstat、lseek也可以：

1. 
   
2. #include <sys\stat.h>;
   
3. #include <string.h>;
   
4. #include <stdio.h>;
   
5. #include <fcntl.h>;
   
6. #include <io.h>;
   
7. 
   
8. int main(void)
   
9. {
   
10.     int handle;
    
11.     char msg[] = "This is a test";
    
12.     char ch;
    
13. 
    
14.     /* create a file */
    
15.     handle = open("TEST.$$$", O_CREAT | O_RDWR, S_IREAD | S_IWRITE);
    
16. 
    
17.     /* write some data to the file */
    
18.     write(handle, msg, strlen(msg));
    
19. 
    
20.     /* seek to the beginning of the file */
    
21.     lseek(handle, 0L, SEEK_SET);
    
22. 
    
23.     /* reads chars from the file until we hit EOF */
    
24. 
    
25.     do
    
26.     {
    
27.        read(handle, &ch, 1);
    
28.        printf("%c", ch);
    
29.     }  while (!eof(handle));
    
30. 
    
31.     close(handle);
    
32.     return 0;
    
33. }
    

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