在C语言中，如何根据目录名求磁盘剩余空间

Question

请教各位大侠：
知道目录名，如何判断（得到）这个目录所在磁盘的剩余空间（用c语言实现）？

Answer 1

帮你顶

Answer 2

通过调用系统命令“df”，然后引用起返回值

Answer 3

df 命令是怎样工作的?我需要作一个独立的命令,不倚赖其它命令.

有没有df的代码实现或他的实现原理?

Answer 4

http://www.koders.com/c/fid9C541A435B215354EA5310CDAE1382D4655E961D.aspx

Answer 5

本帖最后由 yjh777 于 2011-05-09 23:18 编辑

程序中有一个 #include "internal.h"

有没有它的代码，那些结构和函数都不知道是怎么定义的,,
http://www.koders.com/c/fid9C541A435B215354EA5310CDAE1382D4655E961D.aspx
--------------------------------------------------------------------------------------------------------
系统调用:  statfs(2)

1. /* vi: set sw=4 ts=4: */
2. /*
3. * Mini df implementation for busybox
4. *
5. * Copyright (C) 1999,2000 by Lineo, inc.
6. * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
7. * based on original code by (I think) Bruce Perens <bruce@pixar.com>.
8. *
9. * This program is free software; you can redistribute it and/or modify
10. * it under the terms of the GNU General Public License as published by
11. * the Free Software Foundation; either version 2 of the License, or
12. * (at your option) any later version.
13. *
14. * This program is distributed in the hope that it will be useful,
15. * but WITHOUT ANY WARRANTY; without even the implied warranty of
16. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17. * General Public License for more details.
18. *
19. * You should have received a copy of the GNU General Public License
20. * along with this program; if not, write to the Free Software
21. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22. *
23. */
25. #include "internal.h"
26. #include <stdio.h>
27. #include <mntent.h>
28. #include <sys/stat.h>
29. #include <sys/vfs.h>
31. static const char df_usage[] = "df [filesystem ...]\n"
32. #ifndef BB_FEATURE_TRIVIAL_HELP
33.     "\nPrint the filesystem space used and space available.\n"
34. #endif
35.     ;
37. extern const char mtab_file[];    /* Defined in utility.c */
39. static int df(char *device, const char *mountPoint)
40. {
41.     struct statfs s;
42.     long blocks_used;
43.     long blocks_percent_used;
45.     if (statfs(mountPoint, &s) != 0) {
46.         perror(mountPoint);
47.         return FALSE;
48.     }
50.     if (s.f_blocks > 0) {
51.         blocks_used = s.f_blocks - s.f_bfree;
52.         blocks_percent_used = (long)
53.             (blocks_used * 100.0 / (blocks_used + s.f_bavail) + 0.5);
54.         if (strcmp(device, "/dev/root") == 0) {
55.             /* Adjusts device to be the real root device,
56.              * or leaves device alone if it can't find it */
57.             find_real_root_device_name( device);
58.         }
59.         printf("%-20s %9ld %9ld %9ld %3ld%% %s\n",
60.                device,
61.                (long) (s.f_blocks * (s.f_bsize / 1024.0)),
62.                (long) ((s.f_blocks - s.f_bfree) * (s.f_bsize / 1024.0)),
63.                (long) (s.f_bavail * (s.f_bsize / 1024.0)),
64.                blocks_percent_used, mountPoint);
66.     }
68.     return TRUE;
69. }
71. extern int df_main(int argc, char **argv)
72. {
73.     printf("%-20s %-14s %s %s %s %s\n", "Filesystem",
74.            "1k-blocks", "Used", "Available", "Use%", "Mounted on");
76.     if (argc > 1) {
77.         struct mntent *mountEntry;
78.         int status;
80.         if (**(argv + 1) == '-') {
81.             usage(df_usage);
82.         }
83.         while (argc > 1) {
84.             if ((mountEntry = findMountPoint(argv[1], mtab_file)) == 0) {
85.                 fprintf(stderr, "%s: can't find mount point.\n", argv[1]);
86.                 exit(FALSE);
87.             }
88.             status = df(mountEntry->mnt_fsname, mountEntry->mnt_dir);
89.             if (status != 0)
90.                 exit(status);
91.             argc--;
92.             argv++;
93.         }
94.         exit(TRUE);
95.     } else {
96.         FILE *mountTable;
97.         struct mntent *mountEntry;
99.         mountTable = setmntent(mtab_file, "r");
100.         if (mountTable == 0) {
101.             perror(mtab_file);
102.             exit(FALSE);
103.         }
105.         while ((mountEntry = getmntent(mountTable))) {
106.             df(mountEntry->mnt_fsname, mountEntry->mnt_dir);
107.         }
108.         endmntent(mountTable);
109.     }
111.     return(TRUE);
112. }
114. /*
115. Local Variables:
116. c-file-style: "linux"
117. c-basic-offset: 4
118. tab-width: 4
119. End:
120. */

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