BSD 4_3 release

[unix-history] / usr / man / man2 / stat.2

diff --git a/usr/man/man2/stat.2 b/usr/man/man2/stat.2
index e297a1c..ddbd2e8 100644 (file)
--- a/usr/man/man2/stat.2
+++ b/usr/man/man2/stat.2
@@ -1,95 +1,213 @@
-.TH STAT 2 
+.\" Copyright (c) 1980 Regents of the University of California.
+.\" All rights reserved.  The Berkeley software License Agreement
+.\" specifies the terms and conditions for redistribution.
+.\"
+.\"    @(#)stat.2      6.5 (Berkeley) 5/12/86
+.\"
+.TH STAT 2 "May 12, 1986"
+.UC 4

 .SH NAME
 .SH NAME

-stat, fstat \- get file status
+stat, lstat, fstat \- get file status

 .SH SYNOPSIS
 .SH SYNOPSIS

-.B #include <sys/types.h>
-.br
-.B #include <sys/stat.h>
+.nf
+.ft B
+#include <sys/types.h>
+#include <sys/stat.h>
+.PP
+.ft B
+stat(path, buf)
+char *path;
+struct stat *buf;

 .PP
 .PP

-.B stat(name, buf)
-.br
-.B char *name;
-.br
-.B struct stat *buf;
+.ft B
+lstat(path, buf)
+char *path;
+struct stat *buf;

 .PP
 .PP

-.B fstat(fildes, buf)
-.br
-.B struct stat *buf;
+.ft B
+fstat(fd, buf)
+int fd;
+struct stat *buf;
+.fi
+.ft R

 .SH DESCRIPTION
 .I Stat
 .SH DESCRIPTION
 .I Stat

-obtains detailed information about a named file.
+obtains information about the file
+.IR 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 reachable.
+.PP
+.I Lstat
+is like \fIstat\fP except in the case where the named file is a symbolic link,
+in which case
+.I lstat
+returns information about the link,
+while
+.I stat
+returns information about the file the link references.
+.PP

 .I Fstat
 obtains the same information about an open file
 .I Fstat
 obtains the same information about an open file

-known by the file descriptor from a successful
-.I open, creat, dup
-or
-.IR pipe (2)
-call.
+referenced by the argument descriptor, such as would
+be obtained by an \fIopen\fP call.

 .PP
 .PP

-.I Name
-points to a null-terminated string naming
-a file;
+.I Buf
+is a pointer to a
+.I stat
+structure into which information is placed concerning the file.
+The contents of the structure pointed to by

 .I buf
 .I buf

-is the address of a buffer
-into which information is placed concerning the file.
-It is unnecessary to have any
-permissions at all with respect to the file, but all directories
-leading to the file must be searchable.
-The layout of the structure pointed to by buf
-as defined in
-.I <stat.h>
-is given below.
-.I St_mode 
-is encoded according to the `#define' statements.

 .PP
 .nf
 .PP
 .nf

-.so /usr/include/sys/stat.h
+.ta 1i 1.7i 2.5i
+     struct stat {
+       dev_t   st_dev; /* device inode resides on */
+       ino_t   st_ino; /* this inode's number */
+       u_short st_mode;        /* protection */
+       short   st_nlink;       /* number or hard links to the file */
+       short   st_uid; /* user-id of owner */
+       short   st_gid; /* group-id of owner */
+       dev_t   st_rdev;        /* the device type, for inode that is device */
+       off_t   st_size;        /* total size of file */
+       time_t  st_atime;       /* file last access time */
+       int     st_spare1;
+       time_t  st_mtime;       /* file last modify time */
+       int     st_spare2;
+       time_t  st_ctime;       /* file last status change time */
+       int     st_spare3;
+       long    st_blksize;     /* optimal blocksize for file system i/o ops */
+       long    st_blocks;      /* actual number of blocks allocated */
+       long    st_spare4[2];
+    };

 .fi
 .fi

+.DT
+.PP
+.TP 12
+st_atime
+Time when file data was last read or modified.  Changed by the following system
+calls:
+.IR mknod (2),
+.IR utimes (2),
+.IR read (2),
+and
+.IR write (2).
+For reasons of efficiency, 
+st_atime is not set when a directory
+is searched, although this would be more logical.
+.TP 12
+st_mtime
+Time when data was last modified.
+It is not set by changes of owner, group, link count, or mode.
+Changed by the following system calls:
+.IR mknod (2),
+.IR utimes (2),
+.IR write (2).
+.TP 12
+st_ctime
+Time when file status was last changed.
+It is set both both by writing and changing the i-node.
+Changed by the following system calls:
+.IR chmod (2)
+.IR chown (2),
+.IR link (2),
+.IR mknod (2),
+.IR rename (2),
+.IR unlink (2),
+.IR utimes (2),
+.IR write (2).
+.PP
+The status information word \fIst_mode\fP has bits:
+.nf
+.in +5n
+.ta 1.6i 2.5i 3i
+#define S_IFMT 0170000 /* type of file */
+#define\ \ \ \ S_IFDIR 0040000 /* directory */
+#define\ \ \ \ S_IFCHR 0020000 /* character special */
+#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_IREAD        0000400 /* read permission, owner */
+#define S_IWRITE       0000200 /* write permission, owner */
+#define S_IEXEC        0000100 /* execute/search permission, owner */
+.fi
+.in -5n

 .PP
 The mode bits 0000070 and 0000007 encode group and
 others permissions (see
 .IR chmod (2)).
 .PP
 The mode bits 0000070 and 0000007 encode group and
 others permissions (see
 .IR chmod (2)).

-The defined types,
-.I 
-ino_t, off_t, time_t,
-name various width integer values;
-.I dev_t
-encodes
-major and minor device numbers;
-their exact definitions are in
-the include file <sys/types.h>
-(see
-.IR types (5).
-.PP
-When
-.I fildes
-is associated with a pipe,
-.I fstat
-reports an ordinary file with an i-node number,
-restricted permissions,
-and a not necessarily meaningful length.
+.SH "RETURN VALUE
+Upon successful completion a value of 0 is returned.
+Otherwise, a value of \-1 is returned and
+.I errno
+is set to indicate the error.
+.SH "ERRORS
+.I Stat
+and
+.I lstat
+will fail if one or more of the following are true:
+.TP 15
+[ENOTDIR]
+A component of the path prefix is not a directory.
+.TP 15
+[EINVAL]
+The pathname contains a character with the high-order bit set.
+.TP 15
+[ENAMETOOLONG]
+A component of a pathname exceeded 255 characters,
+or an entire path name exceeded 1023 characters.
+.TP 15
+[ENOENT]
+The named file does not exist.
+.TP 15
+[EACCES]
+Search permission is denied for a component of the path prefix.
+.TP 15
+[ELOOP]
+Too many symbolic links were encountered in translating the pathname.
+.TP 15
+[EFAULT]
+.I Buf
+or
+.I name
+points to an invalid address.
+.TP 15
+[EIO]
+An I/O error occurred while reading from or writing to the file system.

 .PP
 .PP

-.I st_atime
-is the file was last read.
-For reasons of efficiency, it is not set when a directory
-is searched, although this would be more logical.
-.I st_mtime
-is the time the file was last written or created.
-It is not set by changes of owner, group, link count, or mode.
-.I st_ctime
-is set both both by writing and changing the i-node.
+.I Fstat
+will fail if one or both of the following are true:
+.TP 15
+[EBADF]
+.I Fildes
+is not a valid open file descriptor.
+.TP 15
+[EFAULT]
+.I Buf
+points to an invalid address.
+.TP 15
+[EIO]
+An I/O error occurred while reading from or writing to the file system.
+.SH CAVEAT
+The fields in the stat structure currently marked 
+.IR st_spare1 ,
+.IR st_spare2 ,
+and
+.I 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
+.IR utimes (2)).

 .SH "SEE ALSO"
 .SH "SEE ALSO"

-ls(1), filsys(5)
-.SH DIAGNOSTICS
-Zero is returned if a status is available;
-\-1 if the file cannot be found.
-.SH ASSEMBLER
-(stat = 18.)
-.br
-.B sys stat; name; buf
-.PP
-(fstat = 28.)
-.br
-(file descriptor in r0)
-.br
-.B sys fstat; buf
+chmod(2), chown(2), utimes(2)
+.SH BUGS
+Applying
+.I 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.