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42 .Fn stat "const char * restrict path" "struct stat * restrict sb"
44 .Fn lstat "const char * restrict path" "struct stat * restrict sb"
46 .Fn fstat "int fd" "struct stat *sb"
48 .Fn fstatat "int fd" "const char *path" "struct stat *sb" "int flag"
52 system call obtains information about the file pointed to by
54 Read, write or execute
55 permission of the named file is not required, but all directories
56 listed in the path name leading to the file must be searchable.
62 except when the named file is a symbolic link,
65 returns information about the link,
68 returns information about the file the link references.
72 system call obtains the same information about an open file
73 known by the file descriptor
78 system call is equivalent to
84 specifies a relative path.
89 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 this 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.
104 .It Dv AT_RESOLVE_BENEATH
105 Only walk paths below the starting directory.
106 See the description of the
107 .Dv O_RESOLVE_BENEATH
114 argument is an empty string, operate on the file or directory
115 referenced by the descriptor
121 operate on the current working directory.
126 is passed the special value
130 parameter, the current working directory is used and the behavior is
131 identical to a call to
135 respectively, depending on whether or not the
136 .Dv AT_SYMLINK_NOFOLLOW
142 is called with an absolute
150 argument is a pointer to a
155 and into which information is placed concerning the file.
159 related to the file system are:
160 .Bl -tag -width ".Va st_nlink"
162 Numeric ID of the device containing the file.
164 The file's inode number.
166 Number of hard links to the file.
168 Flags enabled for the file.
171 for the list of flags and their description.
178 fields together identify the file uniquely within the system.
180 The time-related fields of
183 .Bl -tag -width ".Va st_birthtim"
185 Time when file data was last accessed.
186 Changed implicitly by syscalls such as
193 Time when file data was last modified.
194 Changed implicitly by syscalls such as
201 Also, any syscall which modifies directory content changes the
203 for the affected directory.
212 Time when file status was last changed (inode data modification).
213 Changed implicitly by any syscall that affects file metadata, including
223 Also, any syscall which modifies directory content changes the
225 for the affected directory.
234 Time when the inode was created.
237 These time-related macros are defined for compatibility:
239 #define st_atime st_atim.tv_sec
240 #define st_mtime st_mtim.tv_sec
241 #define st_ctime st_ctim.tv_sec
242 #ifndef _POSIX_SOURCE
243 #define st_birthtime st_birthtim.tv_sec
246 #ifndef _POSIX_SOURCE
247 #define st_atimespec st_atim
248 #define st_mtimespec st_mtim
249 #define st_ctimespec st_ctim
250 #define st_birthtimespec st_birthtim
254 Size-related fields of the
257 .Bl -tag -width ".Va st_blksize"
261 Optimal I/O block size for the file.
263 Actual number of blocks allocated for the file in 512-byte units.
264 As short symbolic links are stored in the inode, this number may
268 The access-related fields of
271 .Bl -tag -width ".Va st_mode"
273 User ID of the file's owner.
275 Group ID of the file.
277 Status of the file (see below).
280 The status information word
284 #define S_IFMT 0170000 /* type of file mask */
285 #define S_IFIFO 0010000 /* named pipe (fifo) */
286 #define S_IFCHR 0020000 /* character special */
287 #define S_IFDIR 0040000 /* directory */
288 #define S_IFBLK 0060000 /* block special */
289 #define S_IFREG 0100000 /* regular */
290 #define S_IFLNK 0120000 /* symbolic link */
291 #define S_IFSOCK 0140000 /* socket */
292 #define S_IFWHT 0160000 /* whiteout */
293 #define S_ISUID 0004000 /* set user id on execution */
294 #define S_ISGID 0002000 /* set group id on execution */
295 #define S_ISVTX 0001000 /* save swapped text even after use */
296 #define S_IRWXU 0000700 /* RWX mask for owner */
297 #define S_IRUSR 0000400 /* read permission, owner */
298 #define S_IWUSR 0000200 /* write permission, owner */
299 #define S_IXUSR 0000100 /* execute/search permission, owner */
300 #define S_IRWXG 0000070 /* RWX mask for group */
301 #define S_IRGRP 0000040 /* read permission, group */
302 #define S_IWGRP 0000020 /* write permission, group */
303 #define S_IXGRP 0000010 /* execute/search permission, group */
304 #define S_IRWXO 0000007 /* RWX mask for other */
305 #define S_IROTH 0000004 /* read permission, other */
306 #define S_IWOTH 0000002 /* write permission, other */
307 #define S_IXOTH 0000001 /* execute/search permission, other */
310 For a list of access modes, see
315 These macros are available to test whether a
319 argument corresponds to a file of the specified type:
320 .Bl -tag -width ".Fn S_ISFIFO m"
322 Test for a block special file.
324 Test for a character special file.
326 Test for a directory.
328 Test for a pipe or FIFO special file.
330 Test for a symbolic link.
332 Test for a regular file.
339 The macros evaluate to a non-zero value if the test is true
340 or to the value 0 if the test is false.
344 Previous versions of the system used different types for the
359 system calls will fail if:
362 Search permission is denied for a component of the path prefix.
369 points to an invalid address.
371 An I/O error occurred while reading from or writing to the file system.
373 Corrupted data was detected while reading from the file system.
375 Too many symbolic links were encountered in translating the pathname.
376 .It Bq Er ENAMETOOLONG
377 A component of a pathname exceeded 255 characters,
378 or an entire path name exceeded 1023 characters.
380 The named file does not exist.
382 A component of the path prefix is not a directory.
384 The file size in bytes cannot be
385 represented correctly in the structure pointed to by
391 system call will fail if:
397 is not a valid open file descriptor.
402 points to an invalid address.
404 An I/O error occurred while reading from or writing to the file system.
406 Corrupted data was detected while reading from the file system.
408 The file size in bytes cannot be
409 represented correctly in the structure pointed to by
413 In addition to the errors returned by the
422 argument does not specify an absolute path and the
426 nor a valid file descriptor open for searching.
430 argument is not valid.
434 argument is not an absolute path and
438 nor a file descriptor associated with a directory.
439 .It Bq Er ENOTCAPABLE
442 or contained a ".." component leading to a
443 directory outside of the directory hierarchy specified by
445 and the process is in capability mode or the
446 .Dv AT_RESOLVE_BENEATH
463 system calls are expected to conform to
467 system call follows The Open Group Extended API Set 2 specification.
473 system calls appeared in
477 system call appeared in
481 system call appeared in
487 returns a zeroed buffer,
488 except for the blocksize field,
489 and a unique device and inode number.