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28 .\" @(#)stat.2 8.4 (Berkeley) 5/1/95
46 .Fn stat "const char *path" "struct stat *sb"
48 .Fn lstat "const char *path" "struct stat *sb"
50 .Fn fstat "int fd" "struct stat *sb"
52 .Fn fstatat "int fd" "const char *path" "struct stat *buf" "int flag"
56 system call obtains information about the file pointed to by
58 Read, write or execute
59 permission of the named file is not required, but all directories
60 listed in the path name leading to the file must be searchable.
66 except in the case where the named file is a symbolic link,
69 returns information about the link,
72 returns information about the file the link references.
76 system call obtains the same information about an open file
77 known by the file descriptor
82 system call is equivalent to
86 except in the case where the
88 specifies a relative path.
89 In this case the status is retrieved from a file relative to
90 the directory associated with the file descriptor
92 instead of the current working directory.
96 are constructed by a bitwise-inclusive OR of flags from the following list,
99 .Bl -tag -width indent
100 .It Dv AT_SYMLINK_NOFOLLOW
103 names a symbolic link, the status of the symbolic link is returned.
108 is passed the special value
112 parameter, the current working directory is used and the behavior is
113 identical to a call to
117 respectively, depending on whether or not the
118 .Dv AT_SYMLINK_NOFOLLOW
124 argument is a pointer to a
129 and into which information is placed concerning the file.
133 related to the file system are as follows:
134 .Bl -tag -width ".Va st_nlink"
136 The numeric ID of the device containing the file.
138 The file's inode number.
140 The number of hard links to the file.
147 fields together identify the file uniquely within the system.
149 The time-related fields of
152 .Bl -tag -width ".Va st_birthtime"
154 Time when file data last accessed.
163 Time when file data last modified.
174 Time when file status was last changed (inode data modification).
195 Time when the inode was created.
200 is not defined, the time-related fields are defined as:
202 #ifndef _POSIX_SOURCE
203 #define st_atime st_atimespec.tv_sec
204 #define st_mtime st_mtimespec.tv_sec
205 #define st_ctime st_ctimespec.tv_sec
209 The size-related fields of the
212 .Bl -tag -width ".Va st_blksize"
214 The file size in bytes.
216 The optimal I/O block size for the file.
218 The actual number of blocks allocated for the file in 512-byte units.
219 As short symbolic links are stored in the inode, this number may
223 The access-related fields of
226 .Bl -tag -width ".Va st_mode"
228 The user ID of the file's owner.
230 The group ID of the file.
232 Status of the file (see below).
235 The status information word
237 has the following bits:
239 #define S_IFMT 0170000 /* type of file mask */
240 #define S_IFIFO 0010000 /* named pipe (fifo) */
241 #define S_IFCHR 0020000 /* character special */
242 #define S_IFDIR 0040000 /* directory */
243 #define S_IFBLK 0060000 /* block special */
244 #define S_IFREG 0100000 /* regular */
245 #define S_IFLNK 0120000 /* symbolic link */
246 #define S_IFSOCK 0140000 /* socket */
247 #define S_IFWHT 0160000 /* whiteout */
248 #define S_ISUID 0004000 /* set user id on execution */
249 #define S_ISGID 0002000 /* set group id on execution */
250 #define S_ISVTX 0001000 /* save swapped text even after use */
251 #define S_IRWXU 0000700 /* RWX mask for owner */
252 #define S_IRUSR 0000400 /* read permission, owner */
253 #define S_IWUSR 0000200 /* write permission, owner */
254 #define S_IXUSR 0000100 /* execute/search permission, owner */
255 #define S_IRWXG 0000070 /* RWX mask for group */
256 #define S_IRGRP 0000040 /* read permission, group */
257 #define S_IWGRP 0000020 /* write permission, group */
258 #define S_IXGRP 0000010 /* execute/search permission, group */
259 #define S_IRWXO 0000007 /* RWX mask for other */
260 #define S_IROTH 0000004 /* read permission, other */
261 #define S_IWOTH 0000002 /* write permission, other */
262 #define S_IXOTH 0000001 /* execute/search permission, other */
265 For a list of access modes, see
270 The following macros are available to test whether a
274 argument corresponds to a file of the specified type:
275 .Bl -tag -width ".Fn S_ISFIFO m"
277 Test for a block special file.
279 Test for a character special file.
281 Test for a directory.
283 Test for a pipe or FIFO special file.
285 Test for a symbolic link.
287 Test for a regular file.
294 The macros evaluate to a non-zero value if the test is true
295 or to the value 0 if the test is false.
299 Previous versions of the system used different types for the
314 system calls will fail if:
317 Search permission is denied for a component of the path prefix.
324 points to an invalid address.
326 An I/O error occurred while reading from or writing to the file system.
328 Too many symbolic links were encountered in translating the pathname.
329 .It Bq Er ENAMETOOLONG
330 A component of a pathname exceeded 255 characters,
331 or an entire path name exceeded 1023 characters.
333 The named file does not exist.
335 A component of the path prefix is not a directory.
337 The file size in bytes cannot be
338 represented correctly in the structure pointed to by
345 system call will fail if:
350 is not a valid open file descriptor.
355 points to an invalid address.
357 An I/O error occurred while reading from or writing to the file system.
359 The file size in bytes cannot be
360 represented correctly in the structure pointed to by
364 In addition to the errors returned by the
373 argument does not specify an absolute path and the
377 nor a valid file descriptor open for searching.
381 argument is not valid.
385 argument is not an absolute path and
389 nor a file descriptor associated with a directory.
405 system calls are expected to conform to
409 system call follows The Open Group Extended API Set 2 specification.
415 system calls appeared in
419 system call appeared in
423 system call appeared in
428 to a socket (and thus to a pipe)
429 returns a zeroed buffer,
430 except for the blocksize field,
431 and a unique device and inode number.