Development and Implementation of a File System for Gannet Virtual ...

nbyte : Maximum number of bytes to read.
Returns:
The number of bytes actually read or -1 on error.
Description:
The read() function reads nbyte bytes from the file associated with fildes into the
buffer pointed to by buf. The read() function returns the number of bytes
actually read and placed in the buffer. This will be less than nbyte if t he
number of bytes left in the file is less than nbyte.
4. write() : Writes to a file.
Arguments:
ssize_t write(int fildes, const void *buf, unsigned int nbyte);
fildes : File descriptor open for writing.
buf : Pointer to the data to be written.
nbyte : Number of bytes to write.
Returns:
The number of bytes written, or -1 to indicate an error.
Description:
The write() function writes nbyte bytes from the array pointed to by buf into the
file associated with fildes. If nbyte is zero and the file is a regular file, the write()
function returns zero and has no other effect.
The write() function returns the number of bytes written. This number will be
less than nbyte if there is an error. It will never be greater than nbyte.
5. close() : Closes a file.
Arguments:
int close(int fildes);
fildes : The file descriptor to close.
Returns:
Zero on success and -1 on failure.
Description:
The close() function deallocates the file descriptor named by fildes and makes it
available for reuse.
6. lseek() : Repositions read/write file offset.
Arguments:
off_t lseek(int fildes, off_t offset, int whence);
fildes : File descriptor to be repositioned.
offset : New offset.
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