struct statvfs, struct statvfs64 -- data structure containing detailed file system information

SYNOPSIS

#include <sys/statvfs.h>

struct statvfs {
	unsigned long f_bsize;
	unsigned long f_frsize;
	fsblkcnt_t f_blocks;
	fsblkcnt_t f_bfree;
	fsblkcnt_t f_bavail;
	fsfilcnt_t f_files;
	fsfilcnt_t f_ffree;
	fsfilcnt_t f_favail;
	unsigned long f_fsid;
	unsigned long f_flag;
	unsigned long f_namemax;
	unsigned long f_type;
	char f_basetype[FSTYPSZ];
	char f_str[FSSTRSZ];
};

struct statvfs64 {
	unsigned long f_bsize;
	unsigned long f_frsize;
	fsblkcnt64_t f_blocks;
	fsblkcnt64_t f_bfree;
	fsblkcnt64_t f_bavail;
	fsfilcnt64_t f_files;
	fsfilcnt64_t f_ffree;
	fsfilcnt64_t f_favail;
	unsigned long f_fsid;
	unsigned long f_flag;
	unsigned long f_namemax;
	unsigned long f_type;
	char f_basetype[FSTYPSZ];
	char f_str[FSSTRSZ];
} statvfs64_t;

DESCRIPTION

The statvfs structure is returned by the fstatvfs() and statvfs() functions. It provides detailed information about a file system. The information returned depends on the type of file system

The statvfs64 structure is identical to the statvfs structure except that it is designed to be used for larger disk volumes where the values to be returned cannot be correctly represented in the datatypes used in the statvfs structure. The statvfs64 structure is returned by the fstatvfs64() and statvfs64() functions, which are a part of the large file extensions.

Fields of the Structure

The statvfs and statvfs64 structure contains the following fields:

f_bsize: File system block size.
f_frsize: Fundamental file system block size (fragment size).
f_blocks: Total number of blocks on the file system, in units of f_frsize.
f_bfree: Total number of free blocks.
f_bavail: Total number of free blocks available to non-privileged processes.
f_files: Total number of file nodes (inodes) on the file system.
f_ffree: Total number of free file nodes (inodes).
f_favail: Total number of free file nodes (inodes) available to non-privileged processes.
f_fsid: File system ID number.
f_flag: Flags, described in the Flags section.
f_namemax: Maximum length of a file name (path element).
f_type: File system type, described in the File System Types section.
f_basetype: File system type name.
f_fstr: File-system-specified string; the first FSSTRSZ bytes of the volume name.

Flags

The st_flag field contains flags that describe properties of the file system:

Flag	Meaning
`ST_RDONLY`	File system is read-only
`ST_NOSUID`	File system does not support setuid/setgid-bit semantics.
`ST_QUOTA`	File system supports quotas.
`ST_NOTRUNC`	File system does not truncate files longer than `NAME_MAX`.
`ST_CASE_PRES`	File system preserves case of file names.
`ST_CASE_SENS`	File system supports case-sensitive file names.
`ST_UNICODE`	File system supports UNICODE path names.
`ST_ACLS`	File system supports persistent ACLs for security.
S`T_FILECOMP`	File system supports per-file compression.
`ST_COMPRESSED`	File system is compressed.
`ST_CRYPT`	File system supports encryption.
`ST_OBJ_IDS`	File system supports object IDs.
`ST_REPARSE`	File system supports reparse points.
`ST_SPARSE`	File system supports sparse files

File System Types

The st_type field contains one of the following values:

Flag	Meaning
`ST_FST_NONE`	File system type could not be determined.
`ST_FST_NFS`	Network File System (NFS).
`ST_FST_FAT`	Traditional 8.3 DOS-style file system
`ST_FST_HPFS`	OS/2 High-Performance File System.
`ST_FST_NTFS`	New Technology File System.
`ST_FST_CDFS`	ISO 9660 CD-ROM file system.
`ST_FST_JOLIET`	Microsoft Joliet CD-ROM format.
`ST_FST_VFAT`	New-style FAT file system with long-name support.
`ST_FST_MVFS`	Rational ClearCase MultiView File System.

CONFORMANCE

UNIX 98, with exceptions.

PORTING ISSUES

Most of the flag values described in the DESCRIPTION section are derived from the Win32 GetVolumeInformation() API function. Refer to the Win32 on-line documentation for more information.

Windows does not support the concept of inodes. Therefore, the f_files, f_ffree, and f_favail fields are not useful, and always contain a large number, to ensure that code that indiscriminately compares against these fields does not fail. There is no reliable way to determine the number of files that can be created on a file system under Windows.

The base Windows 95 operating system, prior to the OEM Service Release 2 (OSR2) version, does not support file systems larger than 2G. Even though the operating system can access larger networked file systems, the function used to determine the size of a file system returns incorrect information. Hence fstatfvs() and statvfs() will return an incorrect size for network file systems larger than 2G. This problem does not occur on 8.1/2012R2/10/2016/2019/11/2022, on Windows 95 OSR2 or later, or on Windows 98/Millennium.

AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

struct statvfs, struct statvfs64
data structure containing detailed file system information

Data Structure