.\" $OpenBSD: stat.2,v 1.3 1997/02/13 05:20:55 millert Exp $ .\" .\" Copyright (c) 1980, 1991, 1993, 1994 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)stat.2 8.3 (Berkeley) 4/19/94 .\" .Dd April 19, 1994 .Dt STAT 2 .Os BSD 4 .Sh NAME .Nm fstat , .Nm lstat , .Nm stat .Nd get file status .Sh SYNOPSIS .Fd #include .Ft int .Fo fstat .Fa "int fildes" .Fa "struct stat *buf" .Fc .Ft int .Fo lstat .Fa "const char *restrict path" .Fa "struct stat *restrict buf" .Fc .Ft int .Fo stat .Fa "const char *restrict path" .Fa "struct stat *restrict buf" .Fc .Sh DESCRIPTION The .Fn stat family of functions obtain information about a file. The .Fn stat function obtains information about the file pointed to by .Fa 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. .Pp .Fn Lstat is like .Fn stat except in the case where the named file is a symbolic link, in which case .Fn lstat returns information about the link, while .Fn stat returns information about the file the link references. Unlike other filesystem objects, symbolic links do not have an owner, group, access mode, times, etc. Instead, these attributes are taken from the directory that contains the link. The only attributes returned from an .Fn lstat that refer to the symbolic link itself are the file type (S_IFLNK), size, blocks, and link count (always 1). .Pp The .Fn fstat obtains the same information about an open file known by the file descriptor .Fa fildes . .Pp The .Fa buf argument is a pointer to a .Fa stat structure as defined by .Aq Pa sys/stat.h and into which information is placed concerning the file. .Bd -literal struct stat { 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! */ }; .Ed .Pp The time-related fields of .Fa struct stat are as follows: .Bl -tag -width XXXst_birthtime .It st_atime Time when file data last accessed. Changed by the .Xr mknod 2 , .Xr utimes 2 and .Xr read 2 system calls. .It st_mtime Time when file data last modified. Changed by the .Xr mknod 2 , .Xr utimes 2 and .Xr write 2 system calls. .It st_ctime Time when file status was last changed (inode data modification). Changed by the .Xr chmod 2 , .Xr chown 2 , .Xr link 2 , .Xr mknod 2 , .Xr rename 2 , .Xr unlink 2 , .Xr utimes 2 and .Xr write 2 system calls. .It st_birthtime Time of file creation. Only set once when the file is created. On filesystems where birthtime is not available, this field holds the .Fa ctime instead. .El .Pp The size-related fields of the structures are as follows: .Bl -tag -width XXXst_blksize .It st_blksize The optimal I/O block size for the file. .It 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. .El .Pp The status information word .Fa st_mode has the following bits: .Bd -literal #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 */ .Ed .Pp For a list of access modes, see .Aq Pa sys/stat.h , .Xr access 2 and .Xr chmod 2 . .Pp For a list of the file flags in the .Fa st_flags field, see .Aq Pa sys/stat.h and .Xr chflags 2 . .Sh RETURN VALUES Upon successful completion a value of 0 is returned. Otherwise, a value of -1 is returned and .Va errno is set to indicate the error. .Sh COMPATIBILITY Previous versions of the system used different types for the .Li st_dev , .Li st_uid , .Li st_gid , .Li st_rdev , .Li st_size , .Li st_blksize and .Li st_blocks fields. .Sh ERRORS .Bl -tag -width Er The .Fn fstat system call will fail if: .\" =========== .It Bq Er EBADF .Fa fildes is not a valid open file descriptor. .\" =========== .It Bq Er EFAULT .Fa Sb points to an invalid address. .\" =========== .It Bq Er EIO An I/O error occurs while reading from or writing to the file system. .El .Pp The .Fn lstat and .Fn stat system calls will fail if: .Bl -tag -width Er .\" =========== .It Bq Er EACCES Search permission is denied for a component of the path prefix. .\" =========== .It Bq Er EFAULT .Fa Sb or .Em name points to an invalid address. .\" =========== .It Bq Er EIO An I/O error occurs while reading from or writing to the file system. .\" =========== .It Bq Er ELOOP Too many symbolic links are encountered in translating the pathname. This is taken to be indicative of a looping symbolic link. .\" =========== .It Bq Er ENAMETOOLONG A component of a pathname exceeds .Dv {NAME_MAX} characters, or an entire path name exceeds .Dv {PATH_MAX} characters. .\" =========== .It Bq Er ENOENT The named file does not exist. .\" =========== .It Bq Er ENOTDIR A component of the path prefix is not a directory. .El .Pp The .Fn fstat , .Fn lstat , and .Fn stat system calls will fail if: .Bl -tag -width Er .\" =========== .It Bq Er 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 .Fa buf . .El .Sh CAVEATS The file generation number, .Fa st_gen , is only available to the super-user. .Sh SEE ALSO .Xr chflags 2 , .Xr chmod 2 , .Xr chown 2 , .Xr utimes 2 , .Xr compat 5 , .Xr symlink 7 .Sh BUGS Applying .Xr 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. .Sh STANDARDS The .Fn stat and .Fn fstat function calls are expected to conform to .St -p1003.1-88 . .Sh HISTORY An .Fn lstat function call appeared in .Bx 4.2 .