mdw@git.distorted.org.uk Git - qmail/blob - fd_copy.3

   1 .TH fd_copy 3
   2 .SH NAME
   3 fd_copy \- duplicate a descriptor
   4 .SH SYNTAX
   5 .B #include <fd.h>
   6
   7 int \fBfd_copy\fP(\fIto\fR,\fIfrom\fR);
   8
   9 int \fIto\fR;
  10 .br
  11 int \fIfrom\fR;
  12 .SH DESCRIPTION
  13 .B fd_copy
  14 copies
  15 descriptor
  16 .I from
  17 to descriptor
  18 .IR to .
  19 If
  20 .I to
  21 was already open,
  22 .B fd_copy
  23 closes it.
  24 .B fd_copy
  25 always leaves
  26 .I from
  27 intact;
  28 if
  29 .I to
  30 and
  31 .I from
  32 are the same number,
  33 .B fd_copy
  34 does nothing.
  35
  36 .B fd_copy
  37 returns 0 on success, -1 on error.
  38 .B fd_copy
  39 does not guarantee that
  40 .I to
  41 will remain open, if it was open, in case of error.
  42 .SH "SEE ALSO"
  43 dup(2),
  44 fd_move(3)