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Diffstat (limited to 'lib/libc/sys/stat.2')
| -rw-r--r-- | lib/libc/sys/stat.2 | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/lib/libc/sys/stat.2 b/lib/libc/sys/stat.2 new file mode 100644 index 0000000..8f78621 --- /dev/null +++ b/lib/libc/sys/stat.2 @@ -0,0 +1,276 @@ +.\" 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 stat , +.Nm lstat , +.Nm fstat +.Nd get file status +.Sh SYNOPSIS +.Fd #include <sys/types.h> +.Fd #include <sys/stat.h> +.Ft int +.Fn stat "const char *path" "struct stat *sb" +.Ft int +.Fn lstat "const char *path" "struct stat *sb" +.Ft int +.Fn fstat "int fd" "struct stat *sb" +.Sh DESCRIPTION +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 fd . +.Pp +The +.Fa sb +argument is a pointer to a +.Fn stat +structure +as defined by +.Aq Pa sys/stat.h +(shown below) +and into which information is placed concerning the file. +.Bd -literal +struct stat { + dev_t st_dev; /* device inode resides on */ + ino_t st_ino; /* inode's number */ + mode_t st_mode; /* inode protection mode */ + nlink_t st_nlink; /* number or hard links to the file */ + uid_t st_uid; /* user-id of owner */ + gid_t st_gid; /* group-id of owner */ + dev_t st_rdev; /* device type, for special file inode */ + struct timespec st_atimespec; /* time of last access */ + struct timespec st_mtimespec; /* time of last data modification */ + struct timespec st_ctimespec; /* time of last file status change */ + off_t st_size; /* file size, in bytes */ + quad_t st_blocks; /* blocks allocated for file */ + u_long st_blksize;/* optimal file sys I/O ops blocksize */ + u_long st_flags; /* user defined flags for file */ + u_long st_gen; /* file generation number */ +}; +.Ed +.Pp +The time-related fields of +.Fa struct stat +are as follows: +.Bl -tag -width XXXst_mtime +.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. +.El +.Pp +The size-related fields of the +.Fa struct stat +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_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 . +.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 +.Fn Stat +and +.Fn lstat +will fail if: +.Bl -tag -width ENAMETOOLONGAA +.It Bq Er ENOTDIR +A component of the path prefix is not a directory. +.It Bq Er EINVAL +The pathname contains a character with the high-order bit set. +.It Bq Er ENAMETOOLONG +A component of a pathname exceeded 255 characters, +or an entire path name exceeded 1023 characters. +.It Bq Er ENOENT +The named file does not exist. +.It Bq Er EACCES +Search permission is denied for a component of the path prefix. +.It Bq Er ELOOP +Too many symbolic links were encountered in translating the pathname. +.It Bq Er EFAULT +.Fa Sb +or +.Em name +points to an invalid address. +.It Bq Er EIO +An I/O error occurred while reading from or writing to the file system. +.El +.Pp +.Bl -tag -width [EFAULT] +.Fn Fstat +will fail if: +.It Bq Er EBADF +.Fa fd +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 occurred while reading from or writing to the file system. +.El +.Sh CAVEAT +The fields in the stat structure currently marked +.Fa st_spare1 , +.Fa st_spare2 , +and +.Fa st_spare3 +are present in preparation for inode time stamps expanding +to 64 bits. This, however, can break certain programs that +depend on the time stamps being contiguous (in calls to +.Xr utimes 2 ) . +.Sh SEE ALSO +.Xr chmod 2 , +.Xr chown 2 , +.Xr utimes 2 +.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 IEEE Std 1003.1-1988 +.Pq Dq Tn POSIX . +.Sh HISTORY +A +.Nm lstat +function call appeared in +.Bx 4.2 . |
