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Reading the Attributes of a File

To examine the attributes of files, use the functions stat, fstat and lstat. They return the attribute information in a struct stat object. All three functions are declared in the header file sys/stat.h.

int stat (const char *filename, struct stat *buf) Function
The stat function returns information about the attributes of the file named by filename in the structure pointed to by buf.

If filename is the name of a symbolic link, the attributes you get describe the file that the link points to. If the link points to a nonexistent file name, then stat fails reporting a nonexistent file.

The return value is 0 if the operation is successful, or -1 on failure. In addition to the usual file name errors (see File Name Errors, the following errno error conditions are defined for this function:

ENOENT
The file named by filename doesn't exist.

When the sources are compiled with _FILE_OFFSET_BITS == 64 this function is in fact stat64 since the LFS interface transparently replaces the normal implementation.

int stat64 (const char *filename, struct stat64 *buf) Function
This function is similar to stat but it is also able to work on files larger then 2^31 bytes on 32-bit systems. To be able to do this the result is stored in a variable of type struct stat64 to which buf must point.

When the sources are compiled with _FILE_OFFSET_BITS == 64 this function is available under the name stat and so transparently replaces the interface for small files on 32-bit machines.

int fstat (int filedes, struct stat *buf) Function
The fstat function is like stat, except that it takes an open file descriptor as an argument instead of a file name. See Low-Level I/O.

Like stat, fstat returns 0 on success and -1 on failure. The following errno error conditions are defined for fstat:

EBADF
The filedes argument is not a valid file descriptor.

When the sources are compiled with _FILE_OFFSET_BITS == 64 this function is in fact fstat64 since the LFS interface transparently replaces the normal implementation.

int fstat64 (int filedes, struct stat64 *buf) Function
This function is similar to fstat but is able to work on large files on 32-bit platforms. For large files the file descriptor filedes should be obtained by open64 or creat64. The buf pointer points to a variable of type struct stat64 which is able to represent the larger values.

When the sources are compiled with _FILE_OFFSET_BITS == 64 this function is available under the name fstat and so transparently replaces the interface for small files on 32-bit machines.

int lstat (const char *filename, struct stat *buf) Function
The lstat function is like stat, except that it does not follow symbolic links. If filename is the name of a symbolic link, lstat returns information about the link itself; otherwise lstat works like stat. See Symbolic Links.

When the sources are compiled with _FILE_OFFSET_BITS == 64 this function is in fact lstat64 since the LFS interface transparently replaces the normal implementation.

int lstat64 (const char *filename, struct stat64 *buf) Function
This function is similar to lstat but it is also able to work on files larger then 2^31 bytes on 32-bit systems. To be able to do this the result is stored in a variable of type struct stat64 to which buf must point.

When the sources are compiled with _FILE_OFFSET_BITS == 64 this function is available under the name lstat and so transparently replaces the interface for small files on 32-bit machines.