---
name: "statvfs"
section: "3"
platform: "macos"
package: "Libc"
version: "1752.120.2"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/statvfs/3"
---

# statvfs(3)

retrieve file system information

## NAME

**fstatvfs**, **statvfs** – retrieve file system information

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<sys/statvfs.h\>**

*int*\

**fstatvfs**(*int fildes*, *struct statvfs \*buf*);

*int*\

**statvfs**(*const char \*restrict path*, *struct statvfs \*restrict buf*);

## DESCRIPTION

The **statvfs**() and **fstatvfs**() functions attempt to fill the structure pointed to by *buf* with file system statistics, but portable applications must not depend on this. Applications must pass a pathname or file descriptor which refers to a file on the file system in which they are interested.

The *statvfs* structure contains the following members:

- *f\_namemax*

  The maximum length in bytes of a file name on this file system. Applications should use [pathconf(2)](/pathconf/2.md) instead.

- *f\_fsid*

  Not meaningful in this implementation.

- *f\_frsize*

  The size in bytes of the minimum unit of allocation on this file system. (This corresponds to the *f\_bsize* member of *struct statfs*.)

- *f\_bsize*

  The preferred length of I/O requests for files on this file system. (Corresponds to the *f\_iosize* member of *struct statfs*.)

- *f\_flag*

  Flags describing mount options for this file system; see below.

In addition, there are three members of type *fsfilcnt\_t*, which represent counts of file serial numbers (*i.e.*, inodes); these are named *f\_files*, *f\_favail*, and *f\_ffree*, and represent the number of file serial numbers which exist in total, are available to unprivileged processes, and are available to privileged processes, respectively. Likewise, the members *f\_blocks*, *f\_bavail*, and *f\_bfree* (all of type *fsblkcnt\_t*) represent the respective allocation-block counts.

There are two flags defined for the *f\_flag* member:

- ST\_RDONLY

  The file system is mounted read-only.

- ST\_NOSUID

  The semantics of the S\_ISUID and S\_ISGID file mode bits are not supported by, or are disabled on, this file system.

## IMPLEMENTATION NOTES

The **statvfs**() and **fstatvfs**() functions are implemented as wrappers around the **statfs**() and **fstatfs**() functions, respectively. Not all the information provided by those functions is made available through this interface.

## RETURN VALUES

The **statvfs()** and **fstatvfs()** functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

## ERRORS

The **statvfs**() function fails if one or more of the following are true:

- \[EACCES\]

  Search permission is denied for a component of the path prefix of *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.

- \[ELOOP\]

  Too many symbolic links were encountered in translating *path*.

- \[ENAMETOOLONG\]

  The length of a component of *path* exceeds  {NAME\_MAX} characters, or the length of *path* exceeds  {PATH\_MAX} characters.

- \[ENOENT\]

  The file referred to by *path* does not exist.

- \[ENOTDIR\]

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

The **fstatvfs**() functions fails if one or more of the following are true:

- \[EBADF\]

  *fildes* 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.

## SEE ALSO

[statfs(2)](/statfs/2.md)

## STANDARDS

The **statvfs**() and **fstatvfs**() functions conform to IEEE Std 1003.1-2001 (“POSIX.1”). As standardized, portable applications cannot depend on these functions returning any valid information at all. This implementation attempts to provide as much useful information as is provided by the underlying file system, subject to the limitations of the specified data types.

## AUTHORS

The **statvfs**() and **fstatvfs**() manual page was originally written by Garrett Wollman ⟨wollman@FreeBSD.org⟩.