bindresvport — bind a socket to a privileged IP port
#include <sys/types.h> #include <netinet/in.h>
int
            bindresvport( | 
            int | sd, | 
| struct sockaddr_in ** | sin); | 
          
bindresvport() is used to
      bind a socket descriptor to a privileged IP port, that is, a
      port number in the range 0-1023.
If in−>sin_port is 0
      then an anonymous port in the range 600 to 1023 be chosen. If
      the bind(2) performed by
      bindresvport() is successful,
      then sin−>sin_port
      returns the port number actually allocated.
sin can be NULL,
      in which case sin−>sin_family is
      implicitly taken to be AF_INET,
      and an anonymous port is allocated (as above). However, in
      this case, bindresvport() has
      no way to return the port number actually allocated.
bindresvport() returns 0 if
      it is successful, otherwise −1 is returned and
      errno set to indicate the cause
      of the error.
Only root can bind to a privileged port; this call will fail for any other users. In addition, the following error may occur:
sin is not
            NULL and sin−>sin_family
            is not AF_INET.
This page is part of release 2.79 of the Linux man-pages project. A
      description of the project, and information about reporting
      bugs, can be found at
      http://www.kernel.org/doc/man-pages/.
| 
                 This page was initially taken from the 4.4BSD-Lite CDROM (BSD license) with substantial updates Copyright (C) 2007, Michael Kerrisk <mtk.manpagesgmail.com> (#)bindresvport.3n 2.2 88/08/02 4.0 RPCSRC; from 1.7 88/03/14 SMI 2007-05-31, mtk: Rewrite and substantial additional text.  |