stat(2) System Calls Manual stat(2)
NAME
stat, fstat, lstat - Provides information about a file
SYNOPSIS
#include <sys/types.h> #include <sys/stat.h>
int stat( const char *path, struct stat *buffer );
int lstat( const char *path, struct stat *buffer );
int fstat( int filedes, struct stat *buffer );
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
fstat(): POSIX.1, XSH5.0
lstat(): POSIX.1, XSH5.0
stat(): POSIX.1, XSH5.0
Refer to the standards(5) reference page for more information about industry standards and associated tags.
PARAMETERS
Specifies the pathname identifying the file. Specifies the file descriptor identifying the open file. Points to the stat structure in
which information is returned. The stat structure is described in the <sys/stat.h> header file.
DESCRIPTION
The stat() function obtains information about the file named by the path parameter. Read, write, or execute permission for the named file
is not required, but all directories listed in the pathname leading to the file must be searchable. The file information is written to the
area specified by the buffer parameter, which is a pointer to a stat structure, defined in sys/stat.h.
The values of the stat structure's member, mode_t, are defined in <sys/mode.h>.
The fstat() function is like the stat() function except that the information obtained is about an open file referenced by the filedes
parameter.
The lstat() function is like the stat() function except in the case where the named file is a symbolic link. In this case, the lstat()
function returns information about the link, while the stat() and fstat() functions return information about the file the link references.
In the case of a symbolic link, the stat() functions set the st_size field of the stat structure to the length of the symbolic link, and
sets the st_mode field to indicate the file type.
The stat(), lstat(), and fstat() functions update any time-related fields associated with the file before writing into the stat structure.
[Tru64 UNIX] When run on a file in an AdvFS clone fileset, the value returned for st_blocks is the number of blocks in the original file
at the time the clone fileset was created.
NOTES
Two structure members in <stat.h> uniquely identify a file in a file system: st_ino, the file serial number, and st_dev, the device id for
the directory that contains the file.
[Tru64 UNIX] However, in the rare case when a user application has been deleting open files, and a file serial number is reused, a third
structure member in <stat.h>, the file generation number, is needed to uniquely identify a file. This member, st_gen, is used in addition
to st_ino and st_dev.
RETURN VALUES
Upon successful completion, a value of 0 (zero) is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS
If the stat() or lstat() function fails, errno may be set to one of the following values: Search permission is denied for a component of
the path parameter. Either the buffer parameter or the path parameter points to a location outside of the allocated address space of the
process. An I/O error occurred while reading from the file system. Too many links were encountered in translating path. The length of
the path parameter exceeds PATH_MAX or a pathname component is longer than NAME_MAX. The file named by the path parameter does not exist
or is an empty string. A component of the path parameter is not a directory. [Tru64 UNIX] The structure pointed to by the buffer argu-
ment cannot correctly represent the value to be returned.
This error occurs in applications compiled either on a system earlier than Tru64 UNIX Version 5.0 or on any system while using the
__V40_OBJ_COMPAT compiler macro. These applications use a <statfs> structure for the for st_blocks fields that is not compatible
with the same structure in Tru64 UNIX Version 5.0.
[Tru64 UNIX] For NFS file access, if the stat() or lstat() function fails, errno may also be set to one of the following values: The file
position pointer associated with the filedes parameter was negative. Indicates either that the request was for a write access to a file
but the specified filename was actually a directory, or that the function was trying to rename a directory as a file. Indicates either
that the system file table is full, or that there are too many files currently open in the system. Indicates a stale NFS file handle. An
opened file was deleted by the server or another client; a client cannot open a file because the server has unmounted or unexported the
remote directory; or the directory that contains an opened file was either unmounted or unexported by the server.
If the fstat() function fails, errno may be set to one of the following values: The filedes parameter is not a valid file descriptor. The
buffer parameter points to a location outside of the allocated address space of the process. An I/O error occurred while reading from the
file system. [Tru64 UNIX] The structure pointed to by the buffer argument cannot correctly represent the value to be returned.
This error occurs in applications compiled either on a system earlier than Tru64 UNIX Version 5.0 or or on any system while using
the __V40_OBJ_COMPAT compiler macro. These applications use a <statfs> structure for st_blocks fields that is not compatible with
the same structure in Tru64 UNIX Version 5.0 or later.
RELATED INFORMATION
Functions: chmod(2), chown(2), link(2), mknod(2), open(2), pipe(2), symlink(2), utime(2)
Standards: standards(5) delim off
stat(2)