#include <sys/types.h> #include <netinet/in.h> int bindresvport(sd, sin) 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. The routine returns 0 if it is successful, otherwise -1 is returned and errno set to reflect the cause of the error. This routine differs with rresvport (see rcmd(3)) in that this works for any IP socket, whereas rresvport() only works for TCP.
Only root can bind to a privileged port; this call will fail for any other users.
rcmd(3) delim off