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, 2021 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. 88For 89.Fn fstatat 90and relative 91.Fa path , 92the status is retrieved from a file relative to 93the directory associated with the file descriptor 94.Fa fd 95instead of the current working directory. 96.Pp 97The values for the 98.Fa flag 99are constructed by a bitwise-inclusive OR of flags from this list, 100defined in 101.In fcntl.h : 102.Bl -tag -width indent 103.It Dv AT_SYMLINK_NOFOLLOW 104If 105.Fa path 106names a symbolic link, the status of the symbolic link is returned. 107.It Dv AT_RESOLVE_BENEATH 108Only walk paths below the starting directory. 109See the description of the 110.Dv O_RESOLVE_BENEATH 111flag in the 112.Xr open 2 113manual page. 114.It Dv AT_EMPTY_PATH 115If the 116.Fa path 117argument is an empty string, operate on the file or directory 118referenced by the descriptor 119.Fa fd . 120If 121.Fa fd 122is equal to 123.Dv AT_FDCWD , 124operate on the current working directory. 125.El 126.Pp 127If 128.Fn fstatat 129is passed the special value 130.Dv AT_FDCWD 131in the 132.Fa fd 133parameter, the current working directory is used and the behavior is 134identical to a call to 135.Fn stat 136or 137.Fn lstat 138respectively, depending on whether or not the 139.Dv AT_SYMLINK_NOFOLLOW 140bit is set in 141.Fa flag . 142.Pp 143When 144.Fn fstatat 145is called with an absolute 146.Fa path , 147it ignores the 148.Fa fd 149argument. 150.Pp 151The 152.Fa sb 153argument is a pointer to a 154.Vt stat 155structure 156as defined by 157.In sys/stat.h 158and into which information is placed concerning the file. 159.Pp 160The fields of 161.Vt "struct stat" 162related to the file system are: 163.Bl -tag -width ".Va st_nlink" 164.It Va st_dev 165Numeric ID of the device containing the file. 166.It Va st_ino 167The file's inode number. 168.It Va st_nlink 169Number of hard links to the file. 170.It Va st_flags 171Flags enabled for the file. 172See 173.Xr chflags 2 174for the list of flags and their description. 175.El 176.Pp 177The 178.Va st_dev 179and 180.Va st_ino 181fields together identify the file uniquely within the system. 182.Pp 183The time-related fields of 184.Vt "struct stat" 185are: 186.Bl -tag -width ".Va st_birthtim" 187.It Va st_atim 188Time when file data was last accessed. 189Changed implicitly by syscalls such as 190.Xr read 2 191and 192.Xr readv 2 , 193and explicitly by 194.Xr utimes 2 . 195.It Va st_mtim 196Time when file data was last modified. 197Changed implicitly by syscalls such as 198.Xr truncate 2 , 199.Xr write 2 , 200and 201.Xr writev 2 , 202and explicitly by 203.Xr utimes 2 . 204Also, any syscall which modifies directory content changes the 205.Va st_mtim 206for the affected directory. 207For instance, 208.Xr creat 2 , 209.Xr mkdir 2 , 210.Xr rename 2 , 211.Xr link 2 , 212and 213.Xr unlink 2 . 214.It Va st_ctim 215Time when file status was last changed (inode data modification). 216Changed implicitly by any syscall that affects file metadata, including 217.Va st_mtim , 218such as 219.Xr chflags 2 , 220.Xr chmod 2 , 221.Xr chown 2 , 222.Xr truncate 2 , 223.Xr utimes 2 , 224and 225.Xr write 2 . 226Also, any syscall which modifies directory content changes the 227.Va st_ctim 228for the affected directory. 229For instance, 230.Xr creat 2 , 231.Xr mkdir 2 , 232.Xr rename 2 , 233.Xr link 2 , 234and 235.Xr unlink 2 . 236.It Va st_birthtim 237Time when the inode was created. 238.El 239.Pp 240These time-related macros are defined for compatibility: 241.Bd -literal 242#define st_atime st_atim.tv_sec 243#define st_mtime st_mtim.tv_sec 244#define st_ctime st_ctim.tv_sec 245#ifndef _POSIX_SOURCE 246#define st_birthtime st_birthtim.tv_sec 247#endif 248 249#ifndef _POSIX_SOURCE 250#define st_atimespec st_atim 251#define st_mtimespec st_mtim 252#define st_ctimespec st_ctim 253#define st_birthtimespec st_birthtim 254#endif 255.Ed 256.Pp 257Size-related fields of the 258.Vt "struct stat" 259are: 260.Bl -tag -width ".Va st_blksize" 261.It Va st_size 262File size in bytes. 263.It Va st_blksize 264Optimal I/O block size for the file. 265.It Va st_blocks 266Actual number of blocks allocated for the file in 512-byte units. 267As short symbolic links are stored in the inode, this number may 268be zero. 269.El 270.Pp 271The access-related fields of 272.Vt "struct stat" 273are: 274.Bl -tag -width ".Va st_mode" 275.It Va st_uid 276User ID of the file's owner. 277.It Va st_gid 278Group ID of the file. 279.It Va st_mode 280Status of the file (see below). 281.El 282.Pp 283The status information word 284.Fa st_mode 285has these bits: 286.Bd -literal 287#define S_IFMT 0170000 /* type of file mask */ 288#define S_IFIFO 0010000 /* named pipe (fifo) */ 289#define S_IFCHR 0020000 /* character special */ 290#define S_IFDIR 0040000 /* directory */ 291#define S_IFBLK 0060000 /* block special */ 292#define S_IFREG 0100000 /* regular */ 293#define S_IFLNK 0120000 /* symbolic link */ 294#define S_IFSOCK 0140000 /* socket */ 295#define S_IFWHT 0160000 /* whiteout */ 296#define S_ISUID 0004000 /* set user id on execution */ 297#define S_ISGID 0002000 /* set group id on execution */ 298#define S_ISVTX 0001000 /* save swapped text even after use */ 299#define S_IRWXU 0000700 /* RWX mask for owner */ 300#define S_IRUSR 0000400 /* read permission, owner */ 301#define S_IWUSR 0000200 /* write permission, owner */ 302#define S_IXUSR 0000100 /* execute/search permission, owner */ 303#define S_IRWXG 0000070 /* RWX mask for group */ 304#define S_IRGRP 0000040 /* read permission, group */ 305#define S_IWGRP 0000020 /* write permission, group */ 306#define S_IXGRP 0000010 /* execute/search permission, group */ 307#define S_IRWXO 0000007 /* RWX mask for other */ 308#define S_IROTH 0000004 /* read permission, other */ 309#define S_IWOTH 0000002 /* write permission, other */ 310#define S_IXOTH 0000001 /* execute/search permission, other */ 311.Ed 312.Pp 313For a list of access modes, see 314.In sys/stat.h , 315.Xr access 2 316and 317.Xr chmod 2 . 318These macros are available to test whether a 319.Va st_mode 320value passed in the 321.Fa m 322argument corresponds to a file of the specified type: 323.Bl -tag -width ".Fn S_ISFIFO m" 324.It Fn S_ISBLK m 325Test for a block special file. 326.It Fn S_ISCHR m 327Test for a character special file. 328.It Fn S_ISDIR m 329Test for a directory. 330.It Fn S_ISFIFO m 331Test for a pipe or FIFO special file. 332.It Fn S_ISLNK m 333Test for a symbolic link. 334.It Fn S_ISREG m 335Test for a regular file. 336.It Fn S_ISSOCK m 337Test for a socket. 338.It Fn S_ISWHT m 339Test for a whiteout. 340.El 341.Pp 342The macros evaluate to a non-zero value if the test is true 343or to the value 0 if the test is false. 344.Sh RETURN VALUES 345.Rv -std 346.Sh COMPATIBILITY 347Previous versions of the system used different types for the 348.Va st_dev , 349.Va st_uid , 350.Va st_gid , 351.Va st_rdev , 352.Va st_size , 353.Va st_blksize 354and 355.Va st_blocks 356fields. 357.Sh ERRORS 358The 359.Fn stat 360and 361.Fn lstat 362system calls will fail if: 363.Bl -tag -width Er 364.It Bq Er EACCES 365Search permission is denied for a component of the path prefix. 366.It Bq Er EFAULT 367The 368.Fa sb 369or 370.Fa path 371argument 372points to an invalid address. 373.It Bq Er EIO 374An I/O error occurred while reading from or writing to the file system. 375.It Bq Er EINTEGRITY 376Corrupted data was detected while reading from the file system. 377.It Bq Er ELOOP 378Too many symbolic links were encountered in translating the pathname. 379.It Bq Er ENAMETOOLONG 380A component of a pathname exceeded 255 characters, 381or an entire path name exceeded 1023 characters. 382.It Bq Er ENOENT 383The named file does not exist. 384.It Bq Er ENOTDIR 385A component of the path prefix is not a directory. 386.It Bq Er EOVERFLOW 387The file size in bytes cannot be 388represented correctly in the structure pointed to by 389.Fa sb . 390.El 391.Pp 392The 393.Fn fstat 394system call will fail if: 395.Bl -tag -width Er 396.It Bq Er EBADF 397The 398.Fa fd 399argument 400is not a valid open file descriptor. 401.It Bq Er EFAULT 402The 403.Fa sb 404argument 405points to an invalid address. 406.It Bq Er EIO 407An I/O error occurred while reading from or writing to the file system. 408.It Bq Er EINTEGRITY 409Corrupted data was detected while reading from the file system. 410.It Bq Er EOVERFLOW 411The file size in bytes cannot be 412represented correctly in the structure pointed to by 413.Fa sb . 414.El 415.Pp 416In addition to the errors returned by the 417.Fn lstat , 418the 419.Fn fstatat 420may fail if: 421.Bl -tag -width Er 422.It Bq Er EBADF 423The 424.Fa path 425argument does not specify an absolute path and the 426.Fa fd 427argument is neither 428.Dv AT_FDCWD 429nor a valid file descriptor open for searching. 430.It Bq Er EINVAL 431The value of the 432.Fa flag 433argument is not valid. 434.It Bq Er ENOTDIR 435The 436.Fa path 437argument is not an absolute path and 438.Fa fd 439is neither 440.Dv AT_FDCWD 441nor a file descriptor associated with a directory. 442.It Bq Er ENOTCAPABLE 443.Fa path 444is an absolute path, 445or contained a ".." component leading to a 446directory outside of the directory hierarchy specified by 447.Fa fd , 448and the process is in capability mode or the 449.Dv AT_RESOLVE_BENEATH 450flag was specified. 451.El 452.Sh SEE ALSO 453.Xr access 2 , 454.Xr chmod 2 , 455.Xr chown 2 , 456.Xr fhstat 2 , 457.Xr statfs 2 , 458.Xr utimes 2 , 459.Xr sticky 7 , 460.Xr symlink 7 461.Sh STANDARDS 462The 463.Fn stat 464and 465.Fn fstat 466system calls are expected to conform to 467.St -p1003.1-90 . 468The 469.Fn fstatat 470system call follows The Open Group Extended API Set 2 specification. 471.Sh HISTORY 472The 473.Fn stat 474and 475.Fn fstat 476system calls appeared in 477.At v1 . 478The 479.Fn lstat 480system call appeared in 481.Bx 4.2 . 482The 483.Fn fstatat 484system call appeared in 485.Fx 8.0 . 486.Sh BUGS 487Applying 488.Fn fstat 489to a socket 490returns a zeroed buffer, 491except for the blocksize field, 492and a unique device and inode number. 493