--- name: "stat" section: "2" platform: "macos" package: "xnu" version: "12377.121.6" release: "macOS 26.5" platforms: ["linux", "freebsd", "macos"] url: "https://new.carta.tech/stat/2" --- # stat(2) get file status ## NAME **fstat**, **fstat64**, **lstat**, **lstat64**, **stat**, **stat64**, **fstatat** – get file status ## SYNOPSIS **#include \** *int*\ **fstat**(*int fildes*, *struct stat \*buf*); *int*\ **lstat**(*const char \*restrict path*, *struct stat \*restrict buf*); *int*\ **stat**(*const char \*restrict path*, *struct stat \*restrict buf*); *int*\ **fstatat**(*int fd*, *const char \*path*, *struct stat \*buf*, *int flag*); ## TRANSITIIONAL SYNOPSIS (NOW DEPRECATED) *int*\ **fstat64**(*int fildes*, *struct stat64 \*buf*); *int*\ **lstat64**(*const char \*restrict path*, *struct stat64 \*restrict buf*); *int*\ **stat64**(*const char \*restrict path*, *struct stat64 \*restrict buf*); ## DESCRIPTION The **stat**() function obtains information about the file pointed to by *path*. Read, write or execute permission of the named file is not required, but all directories listed in the path name leading to the file must be searchable. The **lstat**() function is like **stat**() except in the case where the named file is a symbolic link; **lstat**() returns information about the link, while **stat**() returns information about the file the link references. For symbolic links, the st\_mode member contains meaningful information when used with the file type macros, and the st\_size member contains the length of the pathname contained in the symbolic link. File mode bits and the contents of the remaining members of the stat structure are unspecified. The value returned in the st\_size member is the length of the contents of the symbolic link, and does not count any trailing null. The **fstat**() obtains the same information about an open file known by the file descriptor *fildes*. The **fstatat**() system call is equivalent to **stat**() and **lstat**() except in the case where the *path* specifies a relative path. In this case the status is retrieved from a file relative to the directory associated with the file descriptor *fd* instead of the current working directory. The values for the *flag* are constructed by a bitwise-inclusive OR of flags from the following list, defined in ⟨fcntl.h⟩: - AT\_SYMLINK\_NOFOLLOW If *path* names a symbolic link, the status of the symbolic link is returned. - AT\_SYMLINK\_NOFOLLOW\_ANY If *path* names a symbolic link, the status of the symbolic link is returned. If a symbolic link is encountered during pathname resolution, an error is returned. - AT\_RESOLVE\_BENEATH If *path* does not reside in the hierarchy beneath the starting directory, an error is returned. - AT\_UNIQUE If *path* resolves to a vnode with multiple hard links, an error is returned. If **fstatat**() is passed the special value AT\_FDCWD in the *fd* parameter, the current working directory is used and the behavior is identical to a call to **stat**() or **lstat**() respectively, depending on whether or not the AT\_SYMLINK\_NOFOLLOW bit is set in *flag*. The *buf* argument is a pointer to a *stat* structure as defined by ⟨*sys/stat.h*⟩ and into which information is placed concerning the file. When the macro \_DARWIN\_FEATURE\_64\_BIT\_INODE is not defined (see below for more information about this macro), the *stat* structure is defined as: ``` struct stat { /* when _DARWIN_FEATURE_64_BIT_INODE is NOT defined */ dev_t st_dev; /* device inode resides on */ ino_t st_ino; /* inode's number */ mode_t st_mode; /* inode protection mode */ nlink_t st_nlink; /* number of hard links to the file */ uid_t st_uid; /* user-id of owner */ gid_t st_gid; /* group-id of owner */ dev_t st_rdev; /* device type, for special file inode */ struct timespec st_atimespec; /* time of last access */ struct timespec st_mtimespec; /* time of last data modification */ struct timespec st_ctimespec; /* time of last file status change */ off_t st_size; /* file size, in bytes */ quad_t st_blocks; /* blocks allocated for file */ u_long st_blksize;/* optimal file sys I/O ops blocksize */ u_long st_flags; /* user defined flags for file */ u_long st_gen; /* file generation number */ }; ``` However, when the macro \_DARWIN\_FEATURE\_64\_BIT\_INODE is defined, the *stat* structure will now be defined as: ``` struct stat { /* when _DARWIN_FEATURE_64_BIT_INODE is defined */ dev_t st_dev; /* ID of device containing file */ mode_t st_mode; /* Mode of file (see below) */ nlink_t st_nlink; /* Number of hard links */ ino_t st_ino; /* File serial number */ uid_t st_uid; /* User ID of the file */ gid_t st_gid; /* Group ID of the file */ dev_t st_rdev; /* Device ID */ struct timespec st_atimespec; /* time of last access */ struct timespec st_mtimespec; /* time of last data modification */ struct timespec st_ctimespec; /* time of last status change */ struct timespec st_birthtimespec; /* time of file creation(birth) */ off_t st_size; /* file size, in bytes */ blkcnt_t st_blocks; /* blocks allocated for file */ blksize_t st_blksize; /* optimal blocksize for I/O */ uint32_t st_flags; /* user defined flags for file */ uint32_t st_gen; /* file generation number */ int32_t st_lspare; /* RESERVED: DO NOT USE! */ int64_t st_qspare[2]; /* RESERVED: DO NOT USE! */ }; ``` The time-related fields of *struct*, *stat* are as follows: - st\_atime Time when file data last accessed. Changed by the [mknod(2)](/mknod/2.md), [utimes(2)](/utimes/2.md) and [read(2)](/read/2.md) system calls. - st\_mtime Time when file data last modified. Changed by the [mknod(2)](/mknod/2.md), [utimes(2)](/utimes/2.md) and [write(2)](/write/2.md) system calls. - st\_ctime Time when file status was last changed (inode data modification). Changed by the [chmod(2)](/chmod/2.md), [chown(2)](/chown/2.md), [link(2)](/link/2.md), [mknod(2)](/mknod/2.md), [rename(2)](/rename/2.md), [unlink(2)](/unlink/2.md), [utimes(2)](/utimes/2.md) and [write(2)](/write/2.md) system calls. - st\_birthtime Time of file creation. Only set once when the file is created. This field is only available in the 64 bit inode variants. On filesystems where birthtime is not available, this field is set to 0 (i.e. epoch). The size-related fields of the structures are as follows: - st\_blksize The optimal I/O block size for the file. - st\_blocks The actual number of blocks allocated for the file in 512-byte units. As short symbolic links are stored in the inode, this number may be zero. The status information word *st\_mode* has the following bits: ``` #define S_IFMT 0170000 /* type of file */ #define S_IFIFO 0010000 /* named pipe (fifo) */ #define S_IFCHR 0020000 /* character special */ #define S_IFDIR 0040000 /* directory */ #define S_IFBLK 0060000 /* block special */ #define S_IFREG 0100000 /* regular */ #define S_IFLNK 0120000 /* symbolic link */ #define S_IFSOCK 0140000 /* socket */ #define S_IFWHT 0160000 /* whiteout */ #define S_ISUID 0004000 /* set user id on execution */ #define S_ISGID 0002000 /* set group id on execution */ #define S_ISVTX 0001000 /* save swapped text even after use */ #define S_IRUSR 0000400 /* read permission, owner */ #define S_IWUSR 0000200 /* write permission, owner */ #define S_IXUSR 0000100 /* execute/search permission, owner */ ``` For a list of access modes, see ⟨*sys/stat.h*⟩, [access(2)](/access/2.md) and [chmod(2)](/chmod/2.md). For a list of the file flags in the *st\_flags* field, see ⟨*sys/stat.h*⟩ and [chflags(2)](/chflags/2.md). ## \_DARWIN\_FEATURE\_64\_BIT\_INODE In order to accommodate advanced capabilities of newer file systems, the *struct*, *stat*, *struct*, *statfs*, and *struct*, *dirent* data structures were updated in Mac OSX 10.5. The most obvious change is the increased size of *ino\_t* from 32 bits to 64 bits. As a consequence, storing an ino\_t in an int is no longer safe, and file formats storing ino\_t as 32-bit values may need to be updated. There are other changes as well, such as the widening of *f\_fstypename*, *f\_mntonname*, and *f\_mntfromname* in *struct*, *statfs*. Please refer to [dir(5)](/dir/5.md) for more detail on the specific changes to the other affected data structures. On platforms that existed before these updates were available, ABI compatibility is achieved by providing two implementations for related functions: one using the legacy data structures and one using the updated data structures. Variants which make use of the newer structures have their symbols suffixed with $INODE64. These $INODE64 suffixes are automatically appended by the compiler tool-chain and should not be used directly. Platforms that were released after these updates only have the newer variants available to them. These platforms have the macro \_DARWIN\_FEATURE\_ONLY\_64\_BIT\_INODE defined. The \_DARWIN\_FEATURE\_64\_BIT\_INODE macro should not be set directly. Instead, developers should make use of the \_DARWIN\_NO\_64\_BIT\_INODE or \_DARWIN\_USE\_64\_BIT\_INODE macros when the default variant is not desired. The following table details the effects of defining these macros for different deployment targets. | | | | | | --- | --- | --- | --- | | \_DARWIN\_FEATURE\_ONLY\_64\_BIT\_INODE **not defined** | | | Deployment Target | | user defines: | \< 10.5 | 10.5 | \> 10.5 | | *(none)* | 32-bit | 32-bit | 64-bit | | \_DARWIN\_NO\_64\_BIT\_INODE | 32-bit | 32-bit | 32-bit | | \_DARWIN\_USE\_64\_BIT\_INODE | 32-bit | 64-bit | 64-bit | | | | \_DARWIN\_FEATURE\_ONLY\_64\_BIT\_INODE **defined** | | user defines: | Any Deployment Target | | *(none)* | 64-bit-only | | \_DARWIN\_NO\_64\_BIT\_INODE | *(error)* | | \_DARWIN\_USE\_64\_BIT\_INODE | 64-bit-only | - 32-bit 32-bit inode values are enabled, and the legacy structures involving the *ino\_t* type are in use. The macro \_DARWIN\_FEATURE\_64\_BIT\_INODE is not defined. - 64-bit 64-bit inode values are enabled, and the expanded structures involving the *ino\_t* type are in use. The macro \_DARWIN\_FEATURE\_64\_BIT\_INODE is defined, and loader symbols will contain the $INODE64 suffix. - 64-bit-only Like 64-bit, except loader symbols do not have the $INODE64 suffix. - *(error)* A compile time error is generated. Due to the increased benefits of the larger structure, it is highly recommended that developers not define \_DARWIN\_NO\_64\_BIT\_INODE and make use of \_DARWIN\_USE\_64\_BIT\_INODE when targeting Mac OSX 10.5. In addition to the $INODE64 suffixed symbols, variants suffixed with 64 are also available for related functions. These functions were provided as a way for developers to use the updated structures in code that also made use of the legacy structures. The enlarged stat structures were also prefixed with 64 to distinguish them from their legacy variants. These functions have been deprecated and should be avoided. ## RETURN VALUES Upon successful completion a value of 0 is returned. Otherwise, a value of -1 is returned and *errno* is set to indicate the error. ## COMPATIBILITY Previous versions of the system used different types for the st\_dev, st\_uid, st\_gid, st\_rdev, st\_size, st\_blksize and st\_blocks fields. ## ERRORS The **fstat**() system call will fail if: - \[EBADF\] *fildes* is not a valid open file descriptor. - \[EFAULT\] *Sb* points to an invalid address. - \[EIO\] An I/O error occurs while reading from or writing to the file system. The **lstat**() and **stat**() system calls will fail if: - \[EACCES\] Search permission is denied for a component of the path prefix. - \[EFAULT\] *Sb* or *name* points to an invalid address. - \[EIO\] An I/O error occurs while reading from or writing to the file system. - \[ELOOP\] Too many symbolic links are encountered in translating the pathname. This is taken to be indicative of a looping symbolic link. - \[ELOOP\] If AT\_SYMLINK\_NOFOLLOW\_ANY is passed and symbolic link was encountered during pathname resolution. - \[ENAMETOOLONG\] A component of a pathname exceeds {NAME\_MAX} characters, or an entire path name exceeds {PATH\_MAX} characters. - \[ENOENT\] The named file does not exist. - \[ENOTDIR\] A component of the path prefix is not a directory. The **fstat**(), **lstat**(), and **stat**() system calls will fail if: - \[EOVERFLOW\] The file size in bytes or the number of blocks allocated to the file or the file serial number cannot be represented correctly in the structure pointed to by *buf*. In addition to the errors returned by the **stat**() and **lstat**(), **fstatat**() may fail if: - \[EBADF\] The *path* argument does not specify an absolute path and the *fd* argument is neither AT\_FDCWD nor a valid file descriptor open for searching. - \[EINVAL\] The value of the *flag* argument is not valid. - \[ENOTDIR\] The *path* argument is not an absolute path and *fd* is neither AT\_FDCWD nor a file descriptor associated with a directory. - \[ENOTCAPABLE\] if AT\_RESOLVE\_BENEATH is passed and *path* does not reside in the directory hierarchy beneath the starting directory. - \[ENOTCAPABLE\] if AT\_UNIQUE was passed and *path* resolves to a vnode with multiple links. ## CAVEATS The file generation number, *st\_gen*, is only available to the super-user.\ The fields in the stat structure currently marked *st\_spare1*, *st\_spare2*, and *st\_spare3* are present in preparation for inode time stamps expanding to 64 bits. This, however, can break certain programs that depend on the time stamps being contiguous (in calls to [utimes(2)](/utimes/2.md)). ## TRANSITIONAL DESCRIPTION (NOW DEPRECATED) The *fstat64*, *lstat64* and *stat64* routines are equivalent to their corresponding non-64-suffixed routine, when 64-bit inodes are in effect. They were added before there was support for the symbol variants, and so are now deprecated. Instead of using these, set the \_DARWIN\_USE\_64\_BIT\_INODE macro before including header files to force 64-bit inode support. The *stat64* structure used by these deprecated routines is the same as the *stat* structure when 64-bit inodes are in effect (see above). ## SEE ALSO [chflags(2)](/chflags/2.md), [chmod(2)](/chmod/2.md), [chown(2)](/chown/2.md), [statfs(2)](/statfs/2.md), [utimes(2)](/utimes/2.md), [compat(5)](/compat/5.md), [symlink(7)](/symlink/7.md) ## BUGS Applying **fstat**() to a socket (and thus to a pipe) returns a zero'd buffer, except for the blocksize field, and a unique device and inode number. ## STANDARDS The **stat**() and **fstat**() function calls are expected to conform to IEEE Std 1003.1-1988 (“POSIX.1”). The **fstatat**() system call is expected to conform to POSIX.1-2008 . ## HISTORY An **lstat**() function call appeared in 4.2BSD. The **stat64**(), **fstat64**(), and **lstat64**() system calls first appeared in Mac OS X 10.5 (Leopard) and are now deprecated in favor of the corresponding symbol variants. The **fstatat**() system call appeared in OS X 10.10