4.3BSD-Reno/src/lib/libc/sys/getfsstat.2

.\" Copyright (c) 1989 The Regents of the University of California.
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.\"	@(#)getfsstat.2	6.4 (Berkeley) 6/23/90
.\"
.TH GETFSSTAT 2 "June 23, 1990"
.UC 7
.SH NAME
getfsstat \- get list of all mounted filesystems
.SH SYNOPSIS
.nf
.ft B
#include <sys/types.h>
#include <sys/mount.h>
.LP
.ft B
getfsstat(buf, bufsize, flags)
struct statfs *buf[];
long bufsize;
int flags;
.fi
.ft R
.SH DESCRIPTION
.I Getfsstat
returns information about all mounted filesystems.
.I Buf
is a pointer to an array of
.I statfs
structures defined as follows:
.IP
.ta \w'#define\0\0'u +\w'fsid_t\0\0'u +\w'f_mntfromname[MNAMELEN]\0\0'u
.nf
typedef quad fsid_t;
.sp 1
#define MNAMELEN 32	/* length of buffer for returned name */
.sp 1
struct statfs {
	short	f_type;	/* type of filesystem (see below) */
	short	f_flags;	/* copy of mount flags */
	long	f_fsize;	/* fundamental filesystem block size */
	long	f_bsize;	/* optimal transfer block size */
	long	f_blocks;	/* total data blocks in filesystem */
	long	f_bfree;	/* free blocks in fs */
	long	f_bavail;	/* free blocks avail to non-superuser */
	long	f_files;	/* total file nodes in filesystem */
	long	f_ffree;	/* free file nodes in fs */
	fsid_t	f_fsid;	/* filesystem id */
	long	f_spare[6];	/* spare for later */
	char	f_mntonname[MNAMELEN];	/* directory on which mounted */
	char	f_mntfromname[MNAMELEN];	/* mounted filesystem */
};
/*
 * File system types.
 */
#define	MOUNT_UFS	1
#define	MOUNT_NFS	2
#define	MOUNT_PC	3
.fi
.PP
Fields that are undefined for a particular filesystem are set to \-1.
The buffer is filled with an array of
.I fsstat
structures, one for each mounted filesystem
up to the size specified by
.I bufsize .
.PP
If
.I buf
is given as zero,
.I getfsstat
returns just the number of mounted filesystems.
.PP
Normally
.I flags
should be specified as MNT_WAIT.
If
.I flags
is set to MNT_NOWAIT, then
.I getfsstat
will return the information it has available without requesting
an update from each filesystem.
Thus, some of the information will be out of date, but
.I getfsstat
will not block waiting for information from a filesystem that is
unable to respond.
.SH RETURN VALUE
Upon successful completion, the number of 
.I fsstat
structures is returned.
Otherwise, \-1 is returned and the global variable
.I errno
is set to indicate the error.
.SH ERRORS
.I Getfsstat
fails if one or more of the following are true:
.TP 15
EFAULT
.I Buf
points to an invalid address.
.TP 15
EIO
An I/O error occurred while reading from or writing to the filesystem.
.SH "SEE ALSO"
statfs(2), fstab(5), mount(8)