delete many descriptors
call deletes all descriptors numbered fd and higher
from the per-process file descriptor table. It is effectively the same as
calling close(2) on each descriptor.
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and the global integer variable errno is set to indicate the error.
closefrom() will fail if:
- fd is greater than all open file descriptors.
- An interrupt was received.