rresvport - Retrieve a socket with a privileged address
int *port );
Standard C Library (libc)
Specifies the port to use for the connection.
The rresvport() function obtains a socket with a privileged
address bound to the socket. A privileged Internet
port is one that falls in the range of 0 to 1023.
Only processes with an effective user ID of root can use
the rresvport() function. An authentication scheme based
on remote port numbers is used to verify permissions.
If the connection succeeds, a socket in the Internet
domain of type SOCK_STREAM is returned to the calling process.
Upon successful completion, the rresvport() function
returns a valid, bound socket descriptor. Otherwise, a
value of -1 is returned and errno is set to indicate the
If the rresvport() function fails, errno may be set to one
of the following values: All network ports are in use.
The addresses in the specified address family cannot be
used with this socket. Two hundred (200) file descriptors
are currently open. The system file table is full.
Insufficient buffers are available in the system to complete
Contains the service names.
Functions: rcmd(3), ruserok(3)
[ Back ]