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31.\"	@(#)statfs.2	8.3 (Berkeley) 2/11/94
32.\"
33.Dd February 11, 1994
34.Dt STATFS 2
35.Os
36.Sh NAME
37.Nm statfs
38.Nd get file system statistics
39.Sh SYNOPSIS
40.Fd #include <sys/param.h>
41.Fd #include <sys/mount.h>
42.Ft int
43.Fn statfs "const char *path" "struct statfs *buf"
44.Ft int
45.Fn fstatfs "int fd" "struct statfs *buf"
46.Sh DESCRIPTION
47.Fn statfs
48returns information about a mounted file system.
49.Fa path
50is the path name of any file within the mounted file system.
51.Fa buf
52is a pointer to a
53.Nm statfs
54structure defined as follows:
55.Bd -literal
56typedef struct { int32_t val[2]; } fsid_t;
57
58#define MFSNAMELEN   16 /* length of fs type name, including nul */
59#define MNAMELEN     90	/* length of buffer for returned name */
60
61struct statfs {
62    u_int32_t  f_flags;       /* copy of mount flags */
63    int32_t    f_bsize;       /* fundamental file system block size */
64    u_int32_t  f_iosize;      /* optimal transfer block size */
65    u_int32_t  f_blocks;      /* total data blocks in file system */
66    u_int32_t  f_bfree;       /* free blocks in fs */
67    int32_t    f_bavail;      /* free blocks avail to non-superuser */
68    u_int32_t  f_files;       /* total file nodes in file system */
69    u_int32_t  f_ffree;       /* free file nodes in fs */
70    fsid_t     f_fsid;        /* file system id */
71    uid_t      f_owner;       /* user that mounted the file system */
72    u_int32_t  f_syncwrites;  /* count of sync writes since mount */
73    u_int32_t  f_asyncwrites; /* count of async writes since mount */
74    u_int32_t  f_ctime;       /* last mount [-u] time */
75    u_int32_t  f_spare[3];    /* spare for later */
76    char       f_fstypename[MFSNAMELEN]; /* fs type name */
77    char       f_mntonname[MNAMELEN];    /* directory on which mounted */
78    char       f_mntfromname[MNAMELEN];  /* mounted file system */
79    union mount_info mount_info;         /* per-filesystem mount options */
80};
81.Ed
82.Pp
83.Fn fstatfs
84returns the same information about an open file referenced by descriptor
85.Fa fd .
86.Sh RETURN VALUES
87Upon successful completion, a value of 0 is returned.
88Otherwise, \-1 is returned and the global variable
89.Va errno
90is set to indicate the error.
91.Sh ERRORS
92.Fn statfs
93fails if one or more of the following are true:
94.Bl -tag -width Er
95.It Bq Er ENOTDIR
96A component of the path prefix of
97.Fa path
98is not a directory.
99.It Bq Er ENAMETOOLONG
100The length of a component of
101.Fa path
102exceeds
103.Dv {NAME_MAX}
104characters, or the length of
105.Fa path
106exceeds
107.Dv {PATH_MAX}
108characters.
109.It Bq Er ENOENT
110The file referred to by
111.Fa path
112does not exist.
113.It Bq Er EACCES
114Search permission is denied for a component of the path prefix of
115.Fa path .
116.It Bq Er ELOOP
117Too many symbolic links were encountered in translating
118.Fa path .
119.It Bq Er EFAULT
120.Fa buf
121or
122.Fa path
123points to an invalid address.
124.It Bq Er EIO
125An
126.Tn I/O
127error occurred while reading from or writing to the file system.
128.El
129.Pp
130.Fn fstatfs
131fails if one or more of the following are true:
132.Bl -tag -width Er
133.It Bq Er EBADF
134.Fa fd
135is not a valid open file descriptor.
136.It Bq Er EFAULT
137.Fa buf
138points to an invalid address.
139.It Bq Er EIO
140An
141.Tn I/O
142error occurred while reading from or writing to the file system.
143.El
144.Sh SEE ALSO
145.Xr df 1 ,
146.Xr mount 2 ,
147.Xr stat 2
148.Sh HISTORY
149The
150.Fn statfs
151function first appeared in
152.Bx 4.4 .
153