io_passfd(3) Library Functions Manual io_passfd(3)NAME
io_passfd - pass a file descriptor over a Unix Domain socket
SYNTAX
#include <io.h>
int io_passfd(int64 sock,int64 fd);
DESCRIPTION
io_passfd transfers the file descriptor fd over the Unix Domain socket sock. This works much like dup(2), only that the copy of the
descriptor appears not in this process but at the other end of the Unix Domain socket (which therefore must be a process on the same sys-
tem).
The peer can then use io_receivefd(3) to receive the file descriptor.
Note that the passed descriptor stays open in the sending process.
RETURN VALUE
io_passfd returns 0 on success, -1 on error (setting errno accordingly).
SEE ALSO io_receivefd(3)io_passfd(3)
Check Out this Related Man Page
dup(2) System Calls Manual dup(2)Name
dup, dup2 - duplicate an open file descriptor
Syntax
newd = dup(oldd)
int newd, oldd;
dup2(oldd, newd)
int oldd, newd;
Description
The system call duplicates an existing object descriptor. The argument oldd is a small non-negative integer index in the per-process
descriptor table. The value must be less than the size of the table, which is returned by The new descriptor, newd, returned by the call
is the lowest numbered descriptor that is not currently in use by the process.
The object referenced by the descriptor does not distinguish between references using oldd and newd in any way. Thus, if newd and oldd are
duplicate references to an open file, and calls all move a single pointer into the file. If a separate pointer into the file is desired, a
different object reference to the file must be obtained by issuing an additional call.
In the second form of the call, specify the value of newd needed. If this descriptor is already in use, the descriptor is first deallocated
as if a call had been done.
Return Values
The value -1 is returned if an error occurs in either call. The external variable errno indicates the cause of the error.
Diagnostics
The and system calls fail under the following conditions:
[EBADF] The oldd or newd is not a valid active descriptor.
[EMFILE] Too many descriptors are active.
[EINTR] The or function was terminated prematurely by a signal.
See Alsoaccept(2), close(2), getdtablesize(2), lseek(2), open(2), pipe(2), read(2), socket(2), socketpair(2), write(2)dup(2)
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