386BSD 0.1 development

Work on file usr/othersrc/share/doc/ps1/07.ipctut/dgramread.c

Co-Authored-By: Lynne Greer Jolitz <ljolitz@cardio.ucsf.edu>
Synthesized-from: 386BSD-0.1

diff --git a/usr/othersrc/share/doc/ps1/07.ipctut/dgramread.c b/usr/othersrc/share/doc/ps1/07.ipctut/dgramread.c
new file mode 100644 (file)
index 0000000..e197f09
--- /dev/null
+++ b/usr/othersrc/share/doc/ps1/07.ipctut/dgramread.c
@@ -0,0 +1,83 @@
+.\" Copyright (c) 1986 The Regents of the University of California.
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"    This product includes software developed by the University of
+.\"    California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"    @(#)dgramread.c 6.4 (Berkeley) 4/17/91
+.\"
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <stdio.h>
+
+/*
+ * In the included file <netinet/in.h> a sockaddr_in is defined as follows:
+ * struct sockaddr_in {
+ *     short   sin_family;
+ *     u_short sin_port;
+ *     struct in_addr sin_addr;
+ *     char    sin_zero[8];
+ * }; 
+ *
+ * This program creates a datagram socket, binds a name to it, then reads
+ * from the socket.
+ */
+main()
+{
+       int sock, length;
+       struct sockaddr_in name;
+       char buf[1024];
+
+       /* Create socket from which to read. */
+       sock = socket(AF_INET, SOCK_DGRAM, 0);
+       if (sock < 0) {
+               perror("opening datagram socket");
+               exit(1);
+       }
+       /* Create name with wildcards. */
+       name.sin_family = AF_INET;
+       name.sin_addr.s_addr = INADDR_ANY;
+       name.sin_port = 0;
+       if (bind(sock, &name, sizeof(name))) {
+               perror("binding datagram socket");
+               exit(1);
+       }
+       /* Find assigned port value and print it out. */
+       length = sizeof(name);
+       if (getsockname(sock, &name, &length)) {
+               perror("getting socket name");
+               exit(1);
+       }
+       printf("Socket has port #%d\en", ntohs(name.sin_port));
+       /* Read from the socket */
+       if (read(sock, buf, 1024) < 0)
+               perror("receiving datagram packet");
+       printf("-->%s\en", buf);
+       close(sock);
+}