fd_move.3

linux下qmail的源码 本人加了一些注释

.TH fd_move 3
.SH NAME
fd_move \- renumber a descriptor
.SH SYNTAX
.B #include <fd.h>

int \fBfd_move\fP(\fIto\fR,\fIfrom\fR);

int \fIto\fR;
.br
int \fIfrom\fR;
.SH DESCRIPTION
.B fd_move
moves
descriptor
.I from
to descriptor
.IR to .
If
.I to
was already open,
.B fd_move
closes it.
If the move is successful,
.B fd_move
closes
.IR from .
Exception:
if
.I to
and
.I from
are the same number,
.B fd_move
does nothing.

.B fd_move
returns 0 on success, -1 on error.
.SH "SEE ALSO"
dup(2),
fd_copy(3)