STATFS(2)

NAME
statfs - get file system statistics

SYNOPSIS
#include <sys/param.h>
#include <sys/mount.h>
int
statfs(const char *path, struct statfs *buf);
int
fstatfs(int fd, struct statfs *buf);

DESCRIPTION
Statfs() returns information about a mounted file system. Path is the path name of any file within the mounted filesystem. Buf is a pointer to a statfs() structure defined as follows:

    typedef quad fsid_t;
    #define MNAMELEN 90	/* length of buffer for returned name */
    struct statfs {
    short	f_type;		  /* type of filesystem (see below) */
    short	f_flags;	  /* copy of mount flags */
    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 */
    long	f_spare[9];	  /* spare for later */
    char	f_mntonname[MNAMELEN];	  /* mount point */
    char	f_mntfromname[MNAMELEN];  /* mounted filesystem */
    };
    /*
    * File system types.
    */
    #define	MOUNT_UFS	1	/* Fast Filesystem */
    #define	MOUNT_NFS	2	/* Sun-compatible Network Filesystem */
    #define	MOUNT_MFS	3	/* Memory-based Filesystem */
    #define	MOUNT_MSDOS	4	/* MS/DOS Filesystem */
    #define	MOUNT_LFS	5	/* Log-based Filesystem */
    #define	MOUNT_LOFS	6	/* Loopback Filesystem */
    #define	MOUNT_FDESC	7	/* File Descriptor Filesystem */
    #define	MOUNT_PORTAL	8	/* Portal Filesystem */
    #define MOUNT_NULL	9	/* Minimal Filesystem Layer */
    #define MOUNT_UMAP	10	/* Uid/Gid Remapping Filesystem */
    #define MOUNT_KERNFS	11	/* Kernel Information Filesystem */
    #define MOUNT_PROCFS	12	/* /proc Filesystem */
    #define MOUNT_AFS	13	/* Andrew Filesystem */
    #define MOUNT_CD9660	14	/* ISO9660 (aka CDROM) Filesystem */
    #define MOUNT_UNION	15	/* Union (translucent) Filesystem */

Fields that are undefined for a particular file system are set to -1. Fstatfs() returns the same information about an open file referenced by descriptor fd.

RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, -1 is returned and the global variable errno is set to indicate the error.

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

[ENOTDIR]
    A component of the path prefix of Path is not a directory.

[EINVAL]
    path contains a character with the high-order bit set.

[ENAMETOOLONG]
    The length of a component of path exceeds 255 characters, or the length of path exceeds 1023 characters.

[ENOENT]
    The file referred to by path does not exist.

[EACCES]
    Search permission is denied for a component of the path prefix of path.

[ELOOP]
    Too many symbolic links were encountered in translating path.

[EFAULT]
    Buf or path points to an invalid address.

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

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

[EBADF]
    Fd is not a valid open file descriptor.

[EFAULT]
    Buf points to an invalid address.

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

HISTORY
The statfs function first appeared in 4.4BSD.