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df.c revision 1.17
      1  1.12      cgd /*
      2  1.15  mycroft  * Copyright (c) 1980, 1990, 1993, 1994
      3  1.15  mycroft  *	The Regents of the University of California.  All rights reserved.
      4  1.12      cgd  * (c) UNIX System Laboratories, Inc.
      5  1.12      cgd  * All or some portions of this file are derived from material licensed
      6  1.12      cgd  * to the University of California by American Telephone and Telegraph
      7  1.12      cgd  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
      8  1.12      cgd  * the permission of UNIX System Laboratories, Inc.
      9  1.12      cgd  *
     10  1.12      cgd  * Redistribution and use in source and binary forms, with or without
     11  1.12      cgd  * modification, are permitted provided that the following conditions
     12  1.12      cgd  * are met:
     13  1.12      cgd  * 1. Redistributions of source code must retain the above copyright
     14  1.12      cgd  *    notice, this list of conditions and the following disclaimer.
     15  1.12      cgd  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.12      cgd  *    notice, this list of conditions and the following disclaimer in the
     17  1.12      cgd  *    documentation and/or other materials provided with the distribution.
     18  1.12      cgd  * 3. All advertising materials mentioning features or use of this software
     19  1.12      cgd  *    must display the following acknowledgement:
     20  1.12      cgd  *	This product includes software developed by the University of
     21  1.12      cgd  *	California, Berkeley and its contributors.
     22  1.12      cgd  * 4. Neither the name of the University nor the names of its contributors
     23  1.12      cgd  *    may be used to endorse or promote products derived from this software
     24  1.12      cgd  *    without specific prior written permission.
     25  1.12      cgd  *
     26  1.12      cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  1.12      cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  1.12      cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  1.12      cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  1.12      cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  1.12      cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  1.12      cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  1.12      cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  1.12      cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  1.12      cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  1.12      cgd  * SUCH DAMAGE.
     37  1.12      cgd  */
     38  1.12      cgd 
     39  1.12      cgd #ifndef lint
     40  1.15  mycroft static char copyright[] =
     41  1.15  mycroft "@(#) Copyright (c) 1980, 1990, 1993, 1994\n\
     42  1.15  mycroft 	The Regents of the University of California.  All rights reserved.\n";
     43  1.12      cgd #endif /* not lint */
     44  1.12      cgd 
     45  1.12      cgd #ifndef lint
     46  1.15  mycroft /*static char sccsid[] = "from: @(#)df.c	8.7 (Berkeley) 4/2/94";*/
     47  1.17  mycroft static char rcsid[] = "$Id: df.c,v 1.17 1995/01/30 18:10:51 mycroft Exp $";
     48  1.12      cgd #endif /* not lint */
     49  1.12      cgd 
     50  1.12      cgd #include <sys/param.h>
     51  1.12      cgd #include <sys/stat.h>
     52  1.12      cgd #include <sys/mount.h>
     53  1.15  mycroft 
     54  1.15  mycroft #include <err.h>
     55  1.12      cgd #include <errno.h>
     56  1.12      cgd #include <fcntl.h>
     57  1.12      cgd #include <stdio.h>
     58  1.12      cgd #include <stdlib.h>
     59  1.12      cgd #include <string.h>
     60  1.12      cgd #include <unistd.h>
     61  1.12      cgd 
     62  1.15  mycroft int	 bread __P((off_t, void *, int));
     63  1.12      cgd char	*getmntpt __P((char *));
     64  1.15  mycroft void	 prtstat __P((struct statfs *, int));
     65  1.17  mycroft int	 ufs_df __P((char *, struct statfs *));
     66  1.17  mycroft int	 selected __P((const char *));
     67  1.17  mycroft void	 maketypelist __P((char *));
     68  1.17  mycroft long	 regetmntinfo __P((struct statfs **, long));
     69  1.12      cgd void	 usage __P((void));
     70  1.12      cgd 
     71  1.17  mycroft int	iflag, kflag, lflag, nflag;
     72  1.17  mycroft char	**typelist = NULL;
     73  1.12      cgd struct	ufs_args mdev;
     74  1.12      cgd 
     75  1.12      cgd int
     76  1.12      cgd main(argc, argv)
     77  1.12      cgd 	int argc;
     78  1.12      cgd 	char *argv[];
     79  1.12      cgd {
     80  1.12      cgd 	struct stat stbuf;
     81  1.17  mycroft 	struct statfs statfsbuf, *mntbuf;
     82  1.17  mycroft 	long mntsize;
     83  1.17  mycroft 	int ch, i, maxwidth, width;
     84  1.12      cgd 	char *mntpt;
     85  1.12      cgd 
     86  1.16  mycroft 	while ((ch = getopt(argc, argv, "iklnt:")) != -1)
     87  1.15  mycroft 		switch (ch) {
     88  1.12      cgd 		case 'i':
     89  1.12      cgd 			iflag = 1;
     90  1.12      cgd 			break;
     91  1.12      cgd 		case 'k':
     92  1.12      cgd 			kflag = 1;
     93  1.12      cgd 			break;
     94  1.12      cgd 		case 'l':
     95  1.17  mycroft 			lflag = 1;
     96  1.12      cgd 			break;
     97  1.12      cgd 		case 'n':
     98  1.12      cgd 			nflag = 1;
     99  1.12      cgd 			break;
    100  1.16  mycroft 		case 't':
    101  1.17  mycroft 			if (typelist != NULL)
    102  1.17  mycroft 				errx(1, "only one -t option may be specified.");
    103  1.17  mycroft 			maketypelist(optarg);
    104  1.16  mycroft 			break;
    105  1.12      cgd 		case '?':
    106  1.12      cgd 		default:
    107  1.12      cgd 			usage();
    108  1.12      cgd 		}
    109  1.12      cgd 	argc -= optind;
    110  1.12      cgd 	argv += optind;
    111  1.12      cgd 
    112  1.17  mycroft 	if (*argv && (lflag || typelist != NULL))
    113  1.16  mycroft 		errx(1, "-l or -t does not make sense with list of mount points");
    114  1.12      cgd 
    115  1.17  mycroft 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
    116  1.12      cgd 	if (mntsize == 0)
    117  1.14    glass 	        err(1, "retrieving information on mounted file systems");
    118  1.15  mycroft 
    119  1.12      cgd 	if (!*argv) {
    120  1.17  mycroft 		mntsize = regetmntinfo(&mntbuf, mntsize);
    121  1.17  mycroft 	} else {
    122  1.17  mycroft 		mntbuf = malloc(argc * sizeof(struct statfs));
    123  1.17  mycroft 		mntsize = 0;
    124  1.17  mycroft 		for (; *argv; argv++) {
    125  1.17  mycroft 			if (stat(*argv, &stbuf) < 0) {
    126  1.17  mycroft 				if ((mntpt = getmntpt(*argv)) == 0) {
    127  1.17  mycroft 					warn("%s", *argv);
    128  1.12      cgd 					continue;
    129  1.12      cgd 				}
    130  1.17  mycroft 			} else if ((stbuf.st_mode & S_IFMT) == S_IFCHR) {
    131  1.17  mycroft 				if (!ufs_df(*argv, &mntbuf[mntsize]))
    132  1.17  mycroft 					++mntsize;
    133  1.17  mycroft 				continue;
    134  1.17  mycroft 			} else if ((stbuf.st_mode & S_IFMT) == S_IFBLK) {
    135  1.17  mycroft 				if ((mntpt = getmntpt(*argv)) == 0) {
    136  1.17  mycroft 					mntpt = mktemp(strdup("/tmp/df.XXXXXX"));
    137  1.17  mycroft 					mdev.fspec = *argv;
    138  1.17  mycroft 					if (mkdir(mntpt, DEFFILEMODE) != 0) {
    139  1.17  mycroft 						warn("%s", mntpt);
    140  1.17  mycroft 						continue;
    141  1.17  mycroft 					}
    142  1.17  mycroft 					if (mount(MOUNT_UFS, mntpt, MNT_RDONLY,
    143  1.17  mycroft 					    &mdev) != 0) {
    144  1.17  mycroft 						(void)rmdir(mntpt);
    145  1.17  mycroft 						if (!ufs_df(*argv, &mntbuf[mntsize]))
    146  1.17  mycroft 							++mntsize;
    147  1.17  mycroft 						continue;
    148  1.17  mycroft 					} else if (!statfs(mntpt, &mntbuf[mntsize])) {
    149  1.17  mycroft 						mntbuf[mntsize].f_mntonname[0] = '\0';
    150  1.17  mycroft 						++mntsize;
    151  1.17  mycroft 					} else
    152  1.17  mycroft 						warn("%s", *argv);
    153  1.17  mycroft 					(void)unmount(mntpt, 0);
    154  1.12      cgd 					(void)rmdir(mntpt);
    155  1.12      cgd 					continue;
    156  1.17  mycroft 				}
    157  1.17  mycroft 			} else
    158  1.17  mycroft 				mntpt = *argv;
    159  1.17  mycroft 			/*
    160  1.17  mycroft 			 * Statfs does not take a `wait' flag, so we cannot
    161  1.17  mycroft 			 * implement nflag here.
    162  1.17  mycroft 			 */
    163  1.17  mycroft 			if (!statfs(mntpt, &mntbuf[mntsize]))
    164  1.17  mycroft 				++mntsize;
    165  1.17  mycroft 			else
    166  1.17  mycroft 				warn("%s", *argv);
    167  1.12      cgd 		}
    168  1.12      cgd 	}
    169  1.17  mycroft 
    170  1.17  mycroft 	maxwidth = 0;
    171  1.17  mycroft 	for (i = 0; i < mntsize; i++) {
    172  1.17  mycroft 		width = strlen(mntbuf[i].f_mntfromname);
    173  1.17  mycroft 		if (width > maxwidth)
    174  1.17  mycroft 			maxwidth = width;
    175  1.17  mycroft 	}
    176  1.17  mycroft 	for (i = 0; i < mntsize; i++)
    177  1.17  mycroft 		prtstat(&mntbuf[i], maxwidth);
    178  1.17  mycroft 	exit(0);
    179  1.12      cgd }
    180  1.12      cgd 
    181  1.12      cgd char *
    182  1.12      cgd getmntpt(name)
    183  1.12      cgd 	char *name;
    184  1.12      cgd {
    185  1.17  mycroft 	long mntsize, i;
    186  1.17  mycroft 	struct statfs *mntbuf;
    187  1.12      cgd 
    188  1.17  mycroft 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
    189  1.12      cgd 	for (i = 0; i < mntsize; i++) {
    190  1.12      cgd 		if (!strcmp(mntbuf[i].f_mntfromname, name))
    191  1.12      cgd 			return (mntbuf[i].f_mntonname);
    192  1.12      cgd 	}
    193  1.12      cgd 	return (0);
    194  1.12      cgd }
    195  1.12      cgd 
    196  1.17  mycroft static enum { IN_LIST, NOT_IN_LIST } which;
    197  1.17  mycroft 
    198  1.17  mycroft int
    199  1.17  mycroft selected(type)
    200  1.17  mycroft 	const char *type;
    201  1.17  mycroft {
    202  1.17  mycroft 	char **av;
    203  1.17  mycroft 
    204  1.17  mycroft 	/* If no type specified, it's always selected. */
    205  1.17  mycroft 	if (typelist == NULL)
    206  1.17  mycroft 		return (1);
    207  1.17  mycroft 	for (av = typelist; *av != NULL; ++av)
    208  1.17  mycroft 		if (!strcmp(type, *av))
    209  1.17  mycroft 			return (which == IN_LIST ? 1 : 0);
    210  1.17  mycroft 	return (which == IN_LIST ? 0 : 1);
    211  1.17  mycroft }
    212  1.16  mycroft 
    213  1.16  mycroft void
    214  1.17  mycroft maketypelist(fslist)
    215  1.17  mycroft 	char *fslist;
    216  1.16  mycroft {
    217  1.17  mycroft 	int i;
    218  1.17  mycroft 	char *nextcp, **av;
    219  1.16  mycroft 
    220  1.17  mycroft 	if ((fslist == NULL) || (fslist[0] == '\0'))
    221  1.17  mycroft 		errx(1, "empty type list");
    222  1.16  mycroft 
    223  1.17  mycroft 	/*
    224  1.17  mycroft 	 * XXX
    225  1.17  mycroft 	 * Note: the syntax is "noxxx,yyy" for no xxx's and
    226  1.17  mycroft 	 * no yyy's, not the more intuitive "noyyy,noyyy".
    227  1.17  mycroft 	 */
    228  1.17  mycroft 	if (fslist[0] == 'n' && fslist[1] == 'o') {
    229  1.17  mycroft 		fslist += 2;
    230  1.17  mycroft 		which = NOT_IN_LIST;
    231  1.17  mycroft 	} else
    232  1.17  mycroft 		which = IN_LIST;
    233  1.17  mycroft 
    234  1.17  mycroft 	/* Count the number of types. */
    235  1.17  mycroft 	for (i = 1, nextcp = fslist; nextcp = strchr(nextcp, ','); i++)
    236  1.17  mycroft 		++nextcp;
    237  1.17  mycroft 
    238  1.17  mycroft 	/* Build an array of that many types. */
    239  1.17  mycroft 	if ((av = typelist = malloc((i + 1) * sizeof(char *))) == NULL)
    240  1.17  mycroft 		err(1, NULL);
    241  1.17  mycroft 	av[0] = fslist;
    242  1.17  mycroft 	for (i = 1, nextcp = fslist; nextcp = strchr(nextcp, ','); i++) {
    243  1.17  mycroft 		*nextcp = '\0';
    244  1.17  mycroft 		av[i] = ++nextcp;
    245  1.16  mycroft 	}
    246  1.17  mycroft 	/* Terminate the array. */
    247  1.17  mycroft 	av[i] = NULL;
    248  1.17  mycroft }
    249  1.16  mycroft 
    250  1.17  mycroft /*
    251  1.17  mycroft  * Make a pass over the filesystem info in ``mntbuf'' filtering out
    252  1.17  mycroft  * filesystem types not in ``fsmask'' and possibly re-stating to get
    253  1.17  mycroft  * current (not cached) info.  Returns the new count of valid statfs bufs.
    254  1.17  mycroft  */
    255  1.17  mycroft long
    256  1.17  mycroft regetmntinfo(mntbufp, mntsize)
    257  1.17  mycroft 	struct statfs **mntbufp;
    258  1.17  mycroft 	long mntsize;
    259  1.17  mycroft {
    260  1.17  mycroft 	int i, j;
    261  1.17  mycroft 	struct statfs *mntbuf;
    262  1.16  mycroft 
    263  1.17  mycroft 	if (!lflag && typelist == NULL)
    264  1.17  mycroft 		return (nflag ? mntsize : getmntinfo(mntbufp, MNT_WAIT));
    265  1.16  mycroft 
    266  1.17  mycroft 	mntbuf = *mntbufp;
    267  1.17  mycroft 	j = 0;
    268  1.17  mycroft 	for (i = 0; i < mntsize; i++) {
    269  1.17  mycroft 		if (lflag && (mntbuf[i].f_flags & MNT_LOCAL) == 0)
    270  1.17  mycroft 			continue;
    271  1.17  mycroft 		if (!selected(mntbuf[i].f_fstypename))
    272  1.17  mycroft 			continue;
    273  1.17  mycroft 		if (nflag)
    274  1.17  mycroft 			mntbuf[j] = mntbuf[i];
    275  1.17  mycroft 		else
    276  1.17  mycroft 			(void)statfs(mntbuf[i].f_mntonname, &mntbuf[j]);
    277  1.17  mycroft 		j++;
    278  1.16  mycroft 	}
    279  1.17  mycroft 	return (j);
    280  1.16  mycroft }
    281  1.16  mycroft 
    282  1.12      cgd /*
    283  1.15  mycroft  * Convert statfs returned filesystem size into BLOCKSIZE units.
    284  1.15  mycroft  * Attempts to avoid overflow for large filesystems.
    285  1.15  mycroft  */
    286  1.15  mycroft #define fsbtoblk(num, fsbs, bs) \
    287  1.15  mycroft 	(((fsbs) != 0 && (fsbs) < (bs)) ? \
    288  1.15  mycroft 		(num) / ((bs) / (fsbs)) : (num) * ((fsbs) / (bs)))
    289  1.15  mycroft 
    290  1.15  mycroft /*
    291  1.12      cgd  * Print out status about a filesystem.
    292  1.12      cgd  */
    293  1.12      cgd void
    294  1.12      cgd prtstat(sfsp, maxwidth)
    295  1.15  mycroft 	struct statfs *sfsp;
    296  1.15  mycroft 	int maxwidth;
    297  1.12      cgd {
    298  1.17  mycroft 	static long blocksize;
    299  1.12      cgd 	static int headerlen, timesthrough;
    300  1.12      cgd 	static char *header;
    301  1.12      cgd 	long used, availblks, inodes;
    302  1.12      cgd 
    303  1.12      cgd 	if (maxwidth < 11)
    304  1.12      cgd 		maxwidth = 11;
    305  1.12      cgd 	if (++timesthrough == 1) {
    306  1.12      cgd 		if (kflag) {
    307  1.17  mycroft 			blocksize = 1024;
    308  1.12      cgd 			header = "1K-blocks";
    309  1.12      cgd 			headerlen = strlen(header);
    310  1.12      cgd 		} else
    311  1.12      cgd 			header = getbsize(&headerlen, &blocksize);
    312  1.15  mycroft 		(void)printf("%-*.*s %s     Used    Avail Capacity",
    313  1.12      cgd 		    maxwidth, maxwidth, "Filesystem", header);
    314  1.12      cgd 		if (iflag)
    315  1.12      cgd 			(void)printf(" iused   ifree  %%iused");
    316  1.12      cgd 		(void)printf("  Mounted on\n");
    317  1.12      cgd 	}
    318  1.12      cgd 	(void)printf("%-*.*s", maxwidth, maxwidth, sfsp->f_mntfromname);
    319  1.12      cgd 	used = sfsp->f_blocks - sfsp->f_bfree;
    320  1.12      cgd 	availblks = sfsp->f_bavail + used;
    321  1.15  mycroft 	(void)printf(" %*ld %8ld %8ld", headerlen,
    322  1.15  mycroft 	    fsbtoblk(sfsp->f_blocks, sfsp->f_bsize, blocksize),
    323  1.15  mycroft 	    fsbtoblk(used, sfsp->f_bsize, blocksize),
    324  1.15  mycroft 	    fsbtoblk(sfsp->f_bavail, sfsp->f_bsize, blocksize));
    325  1.12      cgd 	(void)printf(" %5.0f%%",
    326  1.12      cgd 	    availblks == 0 ? 100.0 : (double)used / (double)availblks * 100.0);
    327  1.12      cgd 	if (iflag) {
    328  1.12      cgd 		inodes = sfsp->f_files;
    329  1.12      cgd 		used = inodes - sfsp->f_ffree;
    330  1.12      cgd 		(void)printf(" %7ld %7ld %5.0f%% ", used, sfsp->f_ffree,
    331  1.12      cgd 		   inodes == 0 ? 100.0 : (double)used / (double)inodes * 100.0);
    332  1.12      cgd 	} else
    333  1.12      cgd 		(void)printf("  ");
    334  1.12      cgd 	(void)printf("  %s\n", sfsp->f_mntonname);
    335  1.12      cgd }
    336  1.12      cgd 
    337  1.12      cgd /*
    338  1.15  mycroft  * This code constitutes the pre-system call Berkeley df code for extracting
    339  1.12      cgd  * information from filesystem superblocks.
    340  1.12      cgd  */
    341  1.13   chopps #include <ufs/ffs/fs.h>
    342  1.12      cgd #include <errno.h>
    343  1.12      cgd #include <fstab.h>
    344  1.12      cgd 
    345  1.12      cgd union {
    346  1.12      cgd 	struct fs iu_fs;
    347  1.12      cgd 	char dummy[SBSIZE];
    348  1.12      cgd } sb;
    349  1.12      cgd #define sblock sb.iu_fs
    350  1.12      cgd 
    351  1.15  mycroft int	rfd;
    352  1.12      cgd 
    353  1.17  mycroft int
    354  1.17  mycroft ufs_df(file, sfsp)
    355  1.12      cgd 	char *file;
    356  1.17  mycroft 	struct statfs *sfsp;
    357  1.12      cgd {
    358  1.12      cgd 	char *mntpt;
    359  1.12      cgd 	static int synced;
    360  1.12      cgd 
    361  1.12      cgd 	if (synced++ == 0)
    362  1.12      cgd 		sync();
    363  1.12      cgd 
    364  1.15  mycroft 	if ((rfd = open(file, O_RDONLY)) < 0) {
    365  1.12      cgd 		warn("%s", file);
    366  1.17  mycroft 		return (-1);
    367  1.12      cgd 	}
    368  1.15  mycroft 	if (bread((off_t)SBOFF, &sblock, SBSIZE) == 0) {
    369  1.15  mycroft 		(void)close(rfd);
    370  1.17  mycroft 		return (-1);
    371  1.12      cgd 	}
    372  1.12      cgd 	sfsp->f_type = 0;
    373  1.12      cgd 	sfsp->f_flags = 0;
    374  1.15  mycroft 	sfsp->f_bsize = sblock.fs_fsize;
    375  1.12      cgd 	sfsp->f_iosize = sblock.fs_bsize;
    376  1.12      cgd 	sfsp->f_blocks = sblock.fs_dsize;
    377  1.12      cgd 	sfsp->f_bfree = sblock.fs_cstotal.cs_nbfree * sblock.fs_frag +
    378  1.12      cgd 		sblock.fs_cstotal.cs_nffree;
    379  1.12      cgd 	sfsp->f_bavail = (sblock.fs_dsize * (100 - sblock.fs_minfree) / 100) -
    380  1.12      cgd 		(sblock.fs_dsize - sfsp->f_bfree);
    381  1.12      cgd 	if (sfsp->f_bavail < 0)
    382  1.12      cgd 		sfsp->f_bavail = 0;
    383  1.12      cgd 	sfsp->f_files =  sblock.fs_ncg * sblock.fs_ipg;
    384  1.12      cgd 	sfsp->f_ffree = sblock.fs_cstotal.cs_nifree;
    385  1.12      cgd 	sfsp->f_fsid.val[0] = 0;
    386  1.12      cgd 	sfsp->f_fsid.val[1] = 0;
    387  1.12      cgd 	if ((mntpt = getmntpt(file)) == 0)
    388  1.12      cgd 		mntpt = "";
    389  1.15  mycroft 	memmove(&sfsp->f_mntonname[0], mntpt, MNAMELEN);
    390  1.15  mycroft 	memmove(&sfsp->f_mntfromname[0], file, MNAMELEN);
    391  1.12      cgd 	strncpy(sfsp->f_fstypename, MOUNT_UFS, MFSNAMELEN);
    392  1.12      cgd 	sfsp->f_fstypename[MFSNAMELEN] = '\0';
    393  1.15  mycroft 	(void)close(rfd);
    394  1.17  mycroft 	return (0);
    395  1.12      cgd }
    396  1.12      cgd 
    397  1.12      cgd int
    398  1.12      cgd bread(off, buf, cnt)
    399  1.15  mycroft 	off_t off;
    400  1.15  mycroft 	void *buf;
    401  1.12      cgd 	int cnt;
    402  1.12      cgd {
    403  1.15  mycroft 	int nr;
    404  1.12      cgd 
    405  1.15  mycroft 	(void)lseek(rfd, off, SEEK_SET);
    406  1.15  mycroft 	if ((nr = read(rfd, buf, cnt)) != cnt) {
    407  1.15  mycroft 		/* Probably a dismounted disk if errno == EIO. */
    408  1.15  mycroft 		if (errno != EIO)
    409  1.15  mycroft 			(void)fprintf(stderr, "\ndf: %qd: %s\n",
    410  1.15  mycroft 			    off, strerror(nr > 0 ? EIO : errno));
    411  1.12      cgd 		return (0);
    412  1.12      cgd 	}
    413  1.12      cgd 	return (1);
    414  1.12      cgd }
    415  1.12      cgd 
    416  1.12      cgd void
    417  1.12      cgd usage()
    418  1.12      cgd {
    419  1.16  mycroft 	(void)fprintf(stderr, "usage: df [-ikln] [-t type] [file | file_system ...]\n");
    420  1.12      cgd 	exit(1);
    421  1.12      cgd }
    422