NAME

statvfs, fstatvfs - get file system information

SYNOPSIS

#include <sys/types.h>

#include <sys/statvfs.h>
int statvfs(const char * path, struct statvfs * buf);
int fstatvfs(int fildes, struct statvfs * buf);

DESCRIPTION

The statvfs( ) function returns a "generic superblock" describing a file system; it can be used to acquire information about mounted file systems. buf is a pointer to a structure (described below) that is filled by the function.

path should name a file that resides on that file system. The file system type is known to the operating system. Read, write, or execute permission for the named file is not required, but all directories listed in the path name leading to the file must be searchable.

The statvfs( ) structure pointed to by buf includes the following members:

        u_long       f_bsize;                 /* preferred file system block
                                              size * /
        u_long       f_frsize;                /* fundamental filesystem block
                                              (size if supported) * /
        fsblkcnt_t   f_blocks;                /* total # of blocks on file
                                              system in units of f_frsize * /
        fsblkcnt_t   f_bfree;                 /* total # of free blocks * /
        fsblkcnt_t   f_bavail;                /* # of free blocks avail to
                                              non-super-user * /
        fsfilcnt_t    f_files;                  /* total # of file nodes
                                              (inodes) * /
        fsfilcnt_t    f_ffree;                 /* total # of free file nodes * /
        fsfilcnt_t    f_favail;                /* # of inodes avail to
                                              non-super-user* /
        u_long       f_fsid;                  /* file system id (dev for now) * /
        char         f_basetype[FSTYPSZ];     /* target fs type name,
                                              null-terminated * /
        u_long       f_flag;                   /* bit mask of flags * /
        u_long       f_namemax;               /* maximum file name length * /
        char         f_fstr[32];              /* file system specific string * /
        u_long       f_filler[16];             /* reserved for future expansion * /

f_basetype contains a null-terminated FSType name of the mounted target.

The following flags can be returned in the f_flag field:

ST_RDONLY           0x01              /* read-only file system * /
ST_NOSUID           0x02              /* does not support setuid/setgid
                                      semantics * /
ST_NOTRUNC          0x04              /* does not truncate file names
                                      longer than {NAME_MAX}* /

The fstatvfs( ) function is similar to statvfs( ), except that the file named by path in statvfs( ) is instead identified by an open file descriptor fildes obtained from a successful open(2), creat(2), dup(2), fcntl(2), or pipe(2) function.

RETURN VALUES

Upon successful completion 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS

The statvfs( ) and fstatvfs( ) function will fail if:

EOVERFLOW

One of the values to be returned cannot be represented correctly in the structure pointed to by buf.

The statvfs( ) function will fail if:

EACCES

Search permission is denied on a component of the path prefix.

EFAULT

path or buf points to an illegal address.

EINTR

A signal was caught during statvfs( ) execution.

EIO

An I/O error occurred while reading the file system.

ELOOP

Too many symbolic links were encountered in translating path.

EMULTIHOP

Components of path require hopping to multiple remote machines and file system type does not allow it.

ENAMETOOLONG
                The length of a path component exceeds {NAME_MAX} characters, or the
                length of path The exceeds {PATH_MAX} characters.

ENOENT

Either a component of the path prefix or the file referred to by path does not exist.

ENOLINK

path points to a remote machine and the link to that machine is no longer active.

ENOTDIR

A component of the path prefix of path is not a directory.

The fstatvfs( ) function will fail if:

EBADF

fildes is not an open file descriptor.

EFAULT

buf points to an illegal address.

EINTR

A signal was caught during fstatvfs( ) execution.

EIO

An I/O error occurred while reading the file system.

USAGE

The statvfs( ) and fstatvfs( ) functions have explicit 64-bit equivalents. See interface64(5).

SEE ALSO

chmod(2), chown(2), creat(2), dup(2), fcntl(2), link(2), mknod(2), open(2), pipe(2), read (2),time(2), unlink(2), utime(2), write(2), interface64(5)

BUGS

The values returned for f_files, f_ffree, and f_favail may not be valid for NFS mounted file systems.