struct stat, struct stat64 data structure containing detailed file information	Data Structure
	SYNOPSIS DESCRIPTION Fields of the Structure Flags Access Macros File Type and File System Issues CONFORMANCE PORTING ISSUES AVAILABILITY SEE ALSO

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SYNOPSIS

#include <sys/types.h>

#include <sys/stat.h>

struct stat {
	dev_t st_dev;
	ino_t st_ino;
	mode_t st_mode;
	nlink_t st_nlink;
	uid_t st_uid;
	gid_t st_gid;
	dev_t st_rdev;
	off_t st_size;
	time_t st_atime;
	time_t st_mtime;
	time_t st_ctime;
	blksize_t st_blksize;
	blkcnt_t st_blocks;
	mode_t st_attr;
}; 

struct stat64 {
	dev_t st_dev;
	ino64_t st_ino;
	mode_t st_mode;
	nlink_t st_nlink;
	uid_t st_uid;
	gid_t st_gid;
	dev_t st_rdev;
	off64_t st_size;
	time_t st_atime;
	time_t st_mtime;
	time_t st_ctime;
	blksize_t st_blksize;
	blkcnt64_t st_blocks;
	mode_t st_attr;
}; 

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DESCRIPTION

The stat structure is returned by the fstat() and stat() functions. It provides detailed information about a file. The information returned depends on the type of file and/or the file system on which the file resides.

The stat64 structure is similar to the stat structure, except that it is capable of returning information about files that are larger than 2 gigabytes. The stat64 structure is returned by the fstat64() and stat64() functions, which are a part of the large file extensions.

Fields of the Structure

The stat and stat64 structures contain the following fields:

st_dev  

ID of device containing the file.

st_ino  

Serial number for the file.

st_mode  

Access mode and file type for the file (see Flags).

st_nlink  

Number of links to the file.

st_uid  

User ID of file owner.

st_gid  

Group ID of group owner.

st_rdev  

Device ID (if the file is a character or block special device).

st_size  

File size in bytes (if the file is a regular file).

st_atime  

Time of last access.

st_mtime  

Time of last data modification.

st_ctime  

Time of last file status change.

st_blksize  

A file system-specific preferred I/O block size for this object. On some file system types, this may vary from file to file.

st_blocks  

Number of blocks allocated for this file.

st_attr  

The DOS-style attributes for this file (see Flags). This is a PTC MKS Toolkit UNIX APIs extension.

Flags

The st_mode field contains flags that identify the access mode. There are several NuTCRACKER Platform extensions to the standard access modes, to describe the extended file permissions provided by Windows.

In addition, the st_mode field defines the file type, using the following flags. The macros described in Access Macros should be used rather than directly accessing the bits in st_mode.

The NuTCRACKER Platform stat structure has an st_attr field which specifies the DOS-style attributes for a file, as follows:

Access Macros

The file type can be determined from the stat structure by testing the st_mode field of the structure with the following macros. Each returns a non-zero value if the file is of that type, or 0 if it is not.

File Type and File System Issues

The NuTCRACKER Platform cannot provide a complete stat structure for all files and devices, because of differences in the operating system's representation of the data, and in the implementation of special files. For disk files the following applies:

• The st_dev and st_rdev fields are set to the Volume Serial Number of the file system containing the file, if it can be obtained. Otherwise st_dev is set to 0.
• The st_ino field is reliable only for locally-mounted NTFS file systems. The NuTCRACKER Platform attempts to emulate an inode number based on other file information, but this number cannot be guaranteed to be unique.
• The st_mode field may contain additional permission flag bits as shown in Flags.
• The time fields provide as much information as the underlying file system provides. For example, NTFS supports all three file times, while FAT only supports last-modification time. Note that on a VFAT file system, the last-access time is actually only a date.
• The NuTCRACKER Platform provides an st_attr field which contains the DOS-style file attribute settings, such as hidden or read-only. These bits are shown in Flags.

For special files and devices, you cannot depend on which fields are valid for a given device. The bits in st_mode which indicate the type of the file (for example, the S_ISXXX macros) are always valid.

For symbolic links, the st_mode member contains meaningful information when used with the file type macros, and the st_size member contains the length of the symbolic link. File mode bits and contents of the remaining members of the stat structure are unspecified. The value returned in the st_size member is the length of the contents of the symbolic link, and does not count any trailing null.

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CONFORMANCE

UNIX 98, with exceptions.

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PORTING ISSUES

Because of Windows file system limitations, the NuTCRACKER Platform does not implement the full semantics defined by the referenced standard. Please refer to the File Management section of the Windows Concepts chapter of the PTC MKS Toolkit UNIX to Windows Porting Guide for more information.

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AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

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SEE ALSO

Functions:

_NutFastStat(), chmod(), chown(), fchmod(), fchown(), fcntl(), fstat(), lstat(), mkdir(), mkfifo(), mknod(), stat(), symlink(), umask()

Miscellaneous:

lf64

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PTC MKS Toolkit 10.4 Documentation Build 39.