diff options
Diffstat (limited to 'share/doc/psd/20.ipctut/dgramread.c')
| -rw-r--r-- | share/doc/psd/20.ipctut/dgramread.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/share/doc/psd/20.ipctut/dgramread.c b/share/doc/psd/20.ipctut/dgramread.c new file mode 100644 index 0000000..cd0f147 --- /dev/null +++ b/share/doc/psd/20.ipctut/dgramread.c @@ -0,0 +1,83 @@ +.\" Copyright (c) 1986, 1993 +.\" 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 8.1 (Berkeley) 6/8/93 +.\" +#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); +} |
