source: MondoRescue/branches/stable/mindi-busybox/coreutils/df.c@ 821

/* vi: set sw=4 ts=4: */
/*
 * Mini df implementation for busybox
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 * based on original code by (I think) Bruce Perens <bruce@pixar.com>.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- options -P and -t missing.  Also blocksize. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/df.html */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Size reduction.  Removed floating point dependency.  Added error checking
 * on output.  Output stats on 0-sized filesystems if specifically listed on
 * the command line.  Properly round *-blocks, Used, and Available quantities.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <mntent.h>
#include <sys/vfs.h>
#include "busybox.h"

#ifndef CONFIG_FEATURE_HUMAN_READABLE
static long kscale(long b, long bs)
{
    return ( b * (long long) bs + KILOBYTE/2 ) / KILOBYTE;
}
#endif

int df_main(int argc, char **argv)
{
    long blocks_used;
    long blocks_percent_used;
#ifdef CONFIG_FEATURE_HUMAN_READABLE
    unsigned long df_disp_hr = KILOBYTE;
#endif
    int status = EXIT_SUCCESS;
    unsigned long opt;
    FILE *mount_table;
    struct mntent *mount_entry;
    struct statfs s;
    static const char hdr_1k[] = "1k-blocks"; /* default display is kilobytes */
    const char *disp_units_hdr = hdr_1k;

#ifdef CONFIG_FEATURE_HUMAN_READABLE
    bb_opt_complementally = "h-km:k-hm:m-hk";
    opt = bb_getopt_ulflags(argc, argv, "hmk");
    if(opt & 1) {
                df_disp_hr = 0;
                disp_units_hdr = "     Size";
    }
    if(opt & 2) {
                df_disp_hr = MEGABYTE;
                disp_units_hdr = "1M-blocks";
    }
#else
    opt = bb_getopt_ulflags(argc, argv, "k");
#endif

    bb_printf("Filesystem%11s%-15sUsed Available Use%% Mounted on\n",
              "", disp_units_hdr);

    mount_table = NULL;
    argv += optind;
    if (optind >= argc) {
        if (!(mount_table = setmntent(bb_path_mtab_file, "r"))) {
            bb_perror_msg_and_die(bb_path_mtab_file);
        }
    }

    do {
        const char *device;
        const char *mount_point;

        if (mount_table) {
            if (!(mount_entry = getmntent(mount_table))) {
                endmntent(mount_table);
                break;
            }
        } else {
            if (!(mount_point = *argv++)) {
                break;
            }
            if (!(mount_entry = find_mount_point(mount_point, bb_path_mtab_file))) {
                bb_error_msg("%s: can't find mount point.", mount_point);
            SET_ERROR:
                status = EXIT_FAILURE;
                continue;
            }
        }

        device = mount_entry->mnt_fsname;
        mount_point = mount_entry->mnt_dir;

        if (statfs(mount_point, &s) != 0) {
            bb_perror_msg("%s", mount_point);
            goto SET_ERROR;
        }

        if ((s.f_blocks > 0) || !mount_table){
            blocks_used = s.f_blocks - s.f_bfree;
            blocks_percent_used = 0;
            if (blocks_used + s.f_bavail) {
                blocks_percent_used = (((long long) blocks_used) * 100
                                       + (blocks_used + s.f_bavail)/2
                                       ) / (blocks_used + s.f_bavail);
            }

            if (strcmp(device, "rootfs") == 0) {
                continue;
            } else if (strcmp(device, "/dev/root") == 0) {
                /* Adjusts device to be the real root device,
                * or leaves device alone if it can't find it */
                if ((device = find_block_device("/")) == NULL) {
                    goto SET_ERROR;
                }
            }

#ifdef CONFIG_FEATURE_HUMAN_READABLE
            bb_printf("%-20s %9s ", device,
                      make_human_readable_str(s.f_blocks, s.f_bsize, df_disp_hr));

            bb_printf("%9s ",
                      make_human_readable_str( (s.f_blocks - s.f_bfree),
                                              s.f_bsize, df_disp_hr));

            bb_printf("%9s %3ld%% %s\n",
                      make_human_readable_str(s.f_bavail, s.f_bsize, df_disp_hr),
                      blocks_percent_used, mount_point);
#else
            bb_printf("%-20s %9ld %9ld %9ld %3ld%% %s\n",
                      device,
                      kscale(s.f_blocks, s.f_bsize),
                      kscale(s.f_blocks-s.f_bfree, s.f_bsize),
                      kscale(s.f_bavail, s.f_bsize),
                      blocks_percent_used, mount_point);
#endif
        }

    } while (1);

    bb_fflush_stdout_and_exit(status);
}