delete many descriptors
() call deletes all descriptors numbered
and higher from the per-process file descriptor
table. It is effectively the same as calling
on each descriptor.
Upon successful completion, the value 0 is returned; otherwise the
value -1 is returned and the global variable
errno is set to indicate the error.
closefrom() will fail if:
- fd is greater than all open file descriptors.
- An interrupt was received.
closefrom() is a BSD and Solaris
closefrom() function first appeared in Solaris 9 and
has been available since OpenBSD 3.5.