int write(int fd, const void *buf, unsigned int count);
On success, the number of bytes written are returned. Zero indicates nothing was written. On error, -1 is returned.
fd is not a valid file descriptor or is not open for writing.
bufptr is an invalid pointer value.
An attempt was made to write a file that exceeds the host-specific maximum file size allowed.
No space on device to write the data.
The call was interrupted by the user.