opendarwin man page for getfsstat

GETFSSTAT(2)						      BSD System Calls Manual						      GETFSSTAT(2)

NAME
     getfsstat -- get list of all mounted file systems

SYNOPSIS
     #include <sys/param.h>
     #include <sys/ucred.h>
     #include <sys/mount.h>

     int
     getfsstat(struct statfs *buf, long bufsize, int flags);

DESCRIPTION
     Getfsstat() returns information about all mounted file systems.  Buf is a pointer to an array of statfs structures defined as follows:

     typedef struct { int32_t val[2]; } fsid_t;

     #define MFSNAMELEN   15 /* length of fs type name, not inc. nul */
     #define MNAMELEN	  90 /* length of buffer for returned name */

     struct statfs {
	 short	 f_otype;    /* type of file system (reserved: zero) */
	 short	 f_oflags;   /* copy of mount flags (reserved: zero) */
	 long	 f_bsize;    /* fundamental file system block size */
	 long	 f_iosize;   /* optimal transfer block size */
	 long	 f_blocks;   /* total data blocks in file system */
	 long	 f_bfree;    /* free blocks in fs */
	 long	 f_bavail;   /* free blocks avail to non-superuser */
	 long	 f_files;    /* total file nodes in file system */
	 long	 f_ffree;    /* free file nodes in fs */
	 fsid_t  f_fsid;     /* file system id (super-user only) */
	 uid_t	 f_owner;    /* user that mounted the file system */
	 short	 f_reserved1;	     /* reserved for future use */
	 short	 f_type;     /* type of file system (reserved) */
	 long	 f_flags;    /* copy of mount flags (reserved) */
	 long	 f_reserved2[2];     /* reserved for future use */
	 char	 f_fstypename[MFSNAMELEN]; /* fs type name */
	 char	 f_mntonname[MNAMELEN];    /* directory on which mounted */
	 char	 f_mntfromname[MNAMELEN];  /* mounted file system */
	 char	 f_reserved3;	     /* reserved for future use */
	 long	 f_reserved4[4];     /* reserved for future use */
     };

     Fields that are undefined for a particular file system are set to -1.  The buffer is filled with an array of statfs structures, one for each
     mounted file system up to the size specified by bufsize.

     If buf is given as NULL, getfsstat() returns just the number of mounted file systems.

     Normally flags should be specified as MNT_WAIT.  If flags is set to MNT_NOWAIT, getfsstat() will return the information it has available
     without requesting an update from each file system.  Thus, some of the information will be out of date, but getfsstat() will not block wait-
     ing for information from a file system that is unable to respond.

RETURN VALUES
     Upon successful completion, the number of statfs structures is returned.  Otherwise, -1 is returned and the global variable errno is set to
     indicate the error.

ERRORS
     Getfsstat() fails if one or more of the following are true:

     [EFAULT]		Buf points to an invalid address.

     [EIO]		An I/O error occurred while reading from or writing to the file system.

SEE ALSO
     statfs(2), fstab(5), mount(8)

HISTORY
     The getfsstat() function first appeared in 4.4BSD.

BSD
								   June 9, 1993 							       BSD