1.\" Copyright (c) 1980, 1991, 1993, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)stat.2 8.4 (Berkeley) 5/1/95 29.\" $FreeBSD$ 30.\" 31.Dd March 30, 2020 32.Dt STAT 2 33.Os 34.Sh NAME 35.Nm stat , 36.Nm lstat , 37.Nm fstat , 38.Nm fstatat 39.Nd get file status 40.Sh LIBRARY 41.Lb libc 42.Sh SYNOPSIS 43.In sys/stat.h 44.Ft int 45.Fn stat "const char * restrict path" "struct stat * restrict sb" 46.Ft int 47.Fn lstat "const char * restrict path" "struct stat * restrict sb" 48.Ft int 49.Fn fstat "int fd" "struct stat *sb" 50.Ft int 51.Fn fstatat "int fd" "const char *path" "struct stat *sb" "int flag" 52.Sh DESCRIPTION 53The 54.Fn stat 55system call obtains information about the file pointed to by 56.Fa path . 57Read, write or execute 58permission of the named file is not required, but all directories 59listed in the path name leading to the file must be searchable. 60.Pp 61The 62.Fn lstat 63system call is like 64.Fn stat 65except when the named file is a symbolic link, 66in which case 67.Fn lstat 68returns information about the link, 69while 70.Fn stat 71returns information about the file the link references. 72.Pp 73The 74.Fn fstat 75system call obtains the same information about an open file 76known by the file descriptor 77.Fa fd . 78.Pp 79The 80.Fn fstatat 81system call is equivalent to 82.Fn stat 83and 84.Fn lstat 85except when the 86.Fa path 87specifies a relative path, or the 88.Dv AT_BENEATH 89flag is provided. 90For 91.Fn fstatat 92and relative 93.Fa path , 94the status is retrieved from a file relative to 95the directory associated with the file descriptor 96.Fa fd 97instead of the current working directory. 98For 99.Dv AT_BENEATH 100and absolute 101.Fa path , 102the status is retrieved from a file specified by the 103.Fa path , 104but additional permission checks are performed, see below. 105.Pp 106The values for the 107.Fa flag 108are constructed by a bitwise-inclusive OR of flags from this list, 109defined in 110.In fcntl.h : 111.Bl -tag -width indent 112.It Dv AT_SYMLINK_NOFOLLOW 113If 114.Fa path 115names a symbolic link, the status of the symbolic link is returned. 116.It Dv AT_BENEATH 117Only stat files and directories below the topping directory. 118See the description of the 119.Dv O_BENEATH 120flag in the 121.Xr open 2 122manual page. 123.El 124.Pp 125If 126.Fn fstatat 127is passed the special value 128.Dv AT_FDCWD 129in the 130.Fa fd 131parameter, the current working directory is used and the behavior is 132identical to a call to 133.Fn stat 134or 135.Fn lstat 136respectively, depending on whether or not the 137.Dv AT_SYMLINK_NOFOLLOW 138bit is set in 139.Fa flag . 140.Pp 141When 142.Fn fstatat 143is called with an absolute 144.Fa path 145without the 146.Dv AT_BENEATH 147flag, it ignores the 148.Fa fd 149argument. 150When 151.Dv AT_BENEATH 152is specified with an absolute 153.Fa path , 154a directory passed by the 155.Fa fd 156argument is used as the topping point for the resolution. 157.Pp 158The 159.Fa sb 160argument is a pointer to a 161.Vt stat 162structure 163as defined by 164.In sys/stat.h 165and into which information is placed concerning the file. 166.Pp 167The fields of 168.Vt "struct stat" 169related to the file system are: 170.Bl -tag -width ".Va st_nlink" 171.It Va st_dev 172Numeric ID of the device containing the file. 173.It Va st_ino 174The file's inode number. 175.It Va st_nlink 176Number of hard links to the file. 177.It Va st_flags 178Flags enabled for the file. 179See 180.Xr chflags 2 181for the list of flags and their description. 182.El 183.Pp 184The 185.Va st_dev 186and 187.Va st_ino 188fields together identify the file uniquely within the system. 189.Pp 190The time-related fields of 191.Vt "struct stat" 192are: 193.Bl -tag -width ".Va st_birthtim" 194.It Va st_atim 195Time when file data was last accessed. 196Changed implicitly by syscalls such as 197.Xr read 2 198and 199.Xr readv 2 , 200and explicitly by 201.Xr utimes 2 . 202.It Va st_mtim 203Time when file data was last modified. 204Changed implicitly by syscalls such as 205.Xr truncate 2 , 206.Xr write 2 , 207and 208.Xr writev 2 , 209and explicitly by 210.Xr utimes 2 . 211Also, any syscall which modifies directory content changes the 212.Va st_mtim 213for the affected directory. 214For instance, 215.Xr creat 2 , 216.Xr mkdir 2 , 217.Xr rename 2 , 218.Xr link 2 , 219and 220.Xr unlink 2 . 221.It Va st_ctim 222Time when file status was last changed (inode data modification). 223Changed implicitly by any syscall that affects file metadata, including 224.Va st_mtim , 225such as 226.Xr chflags 2 , 227.Xr chmod 2 , 228.Xr chown 2 , 229.Xr truncate 2 , 230.Xr utimes 2 , 231and 232.Xr write 2 . 233Also, any syscall which modifies directory content changes the 234.Va st_ctim 235for the affected directory. 236For instance, 237.Xr creat 2 , 238.Xr mkdir 2 , 239.Xr rename 2 , 240.Xr link 2 , 241and 242.Xr unlink 2 . 243.It Va st_birthtim 244Time when the inode was created. 245.El 246.Pp 247These time-related macros are defined for compatibility: 248.Bd -literal 249#define st_atime st_atim.tv_sec 250#define st_mtime st_mtim.tv_sec 251#define st_ctime st_ctim.tv_sec 252#ifndef _POSIX_SOURCE 253#define st_birthtime st_birthtim.tv_sec 254#endif 255 256#ifndef _POSIX_SOURCE 257#define st_atimespec st_atim 258#define st_mtimespec st_mtim 259#define st_ctimespec st_ctim 260#define st_birthtimespec st_birthtim 261#endif 262.Ed 263.Pp 264Size-related fields of the 265.Vt "struct stat" 266are: 267.Bl -tag -width ".Va st_blksize" 268.It Va st_size 269File size in bytes. 270.It Va st_blksize 271Optimal I/O block size for the file. 272.It Va st_blocks 273Actual number of blocks allocated for the file in 512-byte units. 274As short symbolic links are stored in the inode, this number may 275be zero. 276.El 277.Pp 278The access-related fields of 279.Vt "struct stat" 280are: 281.Bl -tag -width ".Va st_mode" 282.It Va st_uid 283User ID of the file's owner. 284.It Va st_gid 285Group ID of the file. 286.It Va st_mode 287Status of the file (see below). 288.El 289.Pp 290The status information word 291.Fa st_mode 292has these bits: 293.Bd -literal 294#define S_IFMT 0170000 /* type of file mask */ 295#define S_IFIFO 0010000 /* named pipe (fifo) */ 296#define S_IFCHR 0020000 /* character special */ 297#define S_IFDIR 0040000 /* directory */ 298#define S_IFBLK 0060000 /* block special */ 299#define S_IFREG 0100000 /* regular */ 300#define S_IFLNK 0120000 /* symbolic link */ 301#define S_IFSOCK 0140000 /* socket */ 302#define S_IFWHT 0160000 /* whiteout */ 303#define S_ISUID 0004000 /* set user id on execution */ 304#define S_ISGID 0002000 /* set group id on execution */ 305#define S_ISVTX 0001000 /* save swapped text even after use */ 306#define S_IRWXU 0000700 /* RWX mask for owner */ 307#define S_IRUSR 0000400 /* read permission, owner */ 308#define S_IWUSR 0000200 /* write permission, owner */ 309#define S_IXUSR 0000100 /* execute/search permission, owner */ 310#define S_IRWXG 0000070 /* RWX mask for group */ 311#define S_IRGRP 0000040 /* read permission, group */ 312#define S_IWGRP 0000020 /* write permission, group */ 313#define S_IXGRP 0000010 /* execute/search permission, group */ 314#define S_IRWXO 0000007 /* RWX mask for other */ 315#define S_IROTH 0000004 /* read permission, other */ 316#define S_IWOTH 0000002 /* write permission, other */ 317#define S_IXOTH 0000001 /* execute/search permission, other */ 318.Ed 319.Pp 320For a list of access modes, see 321.In sys/stat.h , 322.Xr access 2 323and 324.Xr chmod 2 . 325These macros are available to test whether a 326.Va st_mode 327value passed in the 328.Fa m 329argument corresponds to a file of the specified type: 330.Bl -tag -width ".Fn S_ISFIFO m" 331.It Fn S_ISBLK m 332Test for a block special file. 333.It Fn S_ISCHR m 334Test for a character special file. 335.It Fn S_ISDIR m 336Test for a directory. 337.It Fn S_ISFIFO m 338Test for a pipe or FIFO special file. 339.It Fn S_ISLNK m 340Test for a symbolic link. 341.It Fn S_ISREG m 342Test for a regular file. 343.It Fn S_ISSOCK m 344Test for a socket. 345.It Fn S_ISWHT m 346Test for a whiteout. 347.El 348.Pp 349The macros evaluate to a non-zero value if the test is true 350or to the value 0 if the test is false. 351.Sh RETURN VALUES 352.Rv -std 353.Sh COMPATIBILITY 354Previous versions of the system used different types for the 355.Va st_dev , 356.Va st_uid , 357.Va st_gid , 358.Va st_rdev , 359.Va st_size , 360.Va st_blksize 361and 362.Va st_blocks 363fields. 364.Sh ERRORS 365The 366.Fn stat 367and 368.Fn lstat 369system calls will fail if: 370.Bl -tag -width Er 371.It Bq Er EACCES 372Search permission is denied for a component of the path prefix. 373.It Bq Er EFAULT 374The 375.Fa sb 376or 377.Fa path 378argument 379points to an invalid address. 380.It Bq Er EIO 381An I/O error occurred while reading from or writing to the file system. 382.It Bq Er EINTEGRITY 383Corrupted data was detected while reading from the file system. 384.It Bq Er ELOOP 385Too many symbolic links were encountered in translating the pathname. 386.It Bq Er ENAMETOOLONG 387A component of a pathname exceeded 255 characters, 388or an entire path name exceeded 1023 characters. 389.It Bq Er ENOENT 390The named file does not exist. 391.It Bq Er ENOTDIR 392A component of the path prefix is not a directory. 393.It Bq Er EOVERFLOW 394The file size in bytes cannot be 395represented correctly in the structure pointed to by 396.Fa sb . 397.El 398.Pp 399The 400.Fn fstat 401system call will fail if: 402.Bl -tag -width Er 403.It Bq Er EBADF 404The 405.Fa fd 406argument 407is not a valid open file descriptor. 408.It Bq Er EFAULT 409The 410.Fa sb 411argument 412points to an invalid address. 413.It Bq Er EIO 414An I/O error occurred while reading from or writing to the file system. 415.It Bq Er EINTEGRITY 416Corrupted data was detected while reading from the file system. 417.It Bq Er EOVERFLOW 418The file size in bytes cannot be 419represented correctly in the structure pointed to by 420.Fa sb . 421.El 422.Pp 423In addition to the errors returned by the 424.Fn lstat , 425the 426.Fn fstatat 427may fail if: 428.Bl -tag -width Er 429.It Bq Er EBADF 430The 431.Fa path 432argument does not specify an absolute path and the 433.Fa fd 434argument is neither 435.Dv AT_FDCWD 436nor a valid file descriptor open for searching. 437.It Bq Er EINVAL 438The value of the 439.Fa flag 440argument is not valid. 441.It Bq Er ENOTDIR 442The 443.Fa path 444argument is not an absolute path and 445.Fa fd 446is neither 447.Dv AT_FDCWD 448nor a file descriptor associated with a directory. 449.It Bq Er ENOTCAPABLE 450.Fa path 451is an absolute path, 452or contained a ".." component leading to a 453directory outside of the directory hierarchy specified by 454.Fa fd , 455and the process is in capability mode. 456.It Bq Er ENOTCAPABLE 457The 458.Dv AT_BENEATH 459flag was provided to 460.Fn fstatat , 461and the absolute 462.Fa path 463does not have its tail fully contained under the topping directory, 464or the relative 465.Fa path 466escapes it. 467.El 468.Sh SEE ALSO 469.Xr access 2 , 470.Xr chmod 2 , 471.Xr chown 2 , 472.Xr fhstat 2 , 473.Xr statfs 2 , 474.Xr utimes 2 , 475.Xr sticky 7 , 476.Xr symlink 7 477.Sh STANDARDS 478The 479.Fn stat 480and 481.Fn fstat 482system calls are expected to conform to 483.St -p1003.1-90 . 484The 485.Fn fstatat 486system call follows The Open Group Extended API Set 2 specification. 487.Sh HISTORY 488The 489.Fn stat 490and 491.Fn fstat 492system calls appeared in 493.At v1 . 494The 495.Fn lstat 496system call appeared in 497.Bx 4.2 . 498The 499.Fn fstatat 500system call appeared in 501.Fx 8.0 . 502.Sh BUGS 503Applying 504.Fn fstat 505to a socket 506returns a zeroed buffer, 507except for the blocksize field, 508and a unique device and inode number. 509