aboutsummaryrefslogtreecommitdiff
path: root/df.c
blob: f8a953f7d20651802d32df67163c4c7e2fad0d8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/*
 * Mini df implementation for busybox
 *
 * Copyright (C) 1999 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 * based on original code by (I think) Bruce Perens <bruce@pixar.com>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "internal.h"
#include <stdio.h>
#include <mntent.h>
#include <sys/stat.h>
#include <sys/vfs.h>
#include <fstab.h>

static const char df_usage[] = "df [filesystem ...]\n"
    "\n" "\tPrint the filesystem space used and space available.\n";


static int df(char *device, const char *mountPoint)
{
    struct statfs s;
    long blocks_used;
    long blocks_percent_used;

    if (statfs(mountPoint, &s) != 0) {
	perror(mountPoint);
	return 1;
    }

    if (s.f_blocks > 0) {
	blocks_used = s.f_blocks - s.f_bfree;
	blocks_percent_used = (long)
	    (blocks_used * 100.0 / (blocks_used + s.f_bavail) + 0.5);
	if (strcmp(device, "/dev/root") == 0)
	    device = (getfsfile("/"))->fs_spec;

	printf("%-20s %9ld %9ld %9ld %3ld%% %s\n",
	       device,
	       (long) (s.f_blocks * (s.f_bsize / 1024.0)),
	       (long) ((s.f_blocks - s.f_bfree) * (s.f_bsize / 1024.0)),
	       (long) (s.f_bavail * (s.f_bsize / 1024.0)),
	       blocks_percent_used, mountPoint);

    }

    return 0;
}

/*
 * Given a block device, find the mount table entry if that block device
 * is mounted.
 *
 * Given any other file (or directory), find the mount table entry for its
 * filesystem.
 */
extern struct mntent *findMountPoint(const char *name, const char *table)
{
    struct stat s;
    dev_t mountDevice;
    FILE *mountTable;
    struct mntent *mountEntry;

    if (stat(name, &s) != 0)
	return 0;

    if ((s.st_mode & S_IFMT) == S_IFBLK)
	mountDevice = s.st_rdev;
    else
	mountDevice = s.st_dev;


    if ((mountTable = setmntent(table, "r")) == 0)
	return 0;

    while ((mountEntry = getmntent(mountTable)) != 0) {
	if (strcmp(name, mountEntry->mnt_dir) == 0
	    || strcmp(name, mountEntry->mnt_fsname) == 0)	/* String match. */
	    break;
	if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == mountDevice)	/* Match the device. */
	    break;
	if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == mountDevice)	/* Match the directory's mount point. */
	    break;
    }
    endmntent(mountTable);
    return mountEntry;
}



extern int df_main(int argc, char **argv)
{
    printf("%-20s %-14s %s %s %s %s\n", "Filesystem",
	   "1k-blocks", "Used", "Available", "Use%", "Mounted on");

    if (argc > 1) {
	struct mntent *mountEntry;
	int status;

	while (argc > 1) {
	    if ((mountEntry = findMountPoint(argv[1], "/proc/mounts")) ==
		0) {
		fprintf(stderr, "%s: can't find mount point.\n", argv[1]);
		return 1;
	    }
	    status = df(mountEntry->mnt_fsname, mountEntry->mnt_dir);
	    if (status != 0)
		return status;
	    argc--;
	    argv++;
	}
	return 0;
    } else {
	FILE *mountTable;
	struct mntent *mountEntry;

	mountTable = setmntent("/proc/mounts", "r");
	if (mountTable == 0) {
	    perror("/proc/mounts");
	    exit(FALSE);
	}

	while ((mountEntry = getmntent(mountTable))) {
	    int status = df(mountEntry->mnt_fsname, mountEntry->mnt_dir);
	    if (status)
		return status;
	}
	endmntent(mountTable);
    }

    return 0;
}