Gathers the statistics of the file opened by the file pointer fp. This function is similar to the stat() function except that it operates on an open file pointer instead of a filename.
Returns an array with the statistics of the file with the following elements:
device
inode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated
The results of this function are cached. See clearstatcache() for more details.