ARM和Linux下 nanomsg 编译与使用

简介

首页：https://nanomsg.org/index.html

nanomsg是一个套接字库，提供了几种常见的通信模式。它旨在使网络层快速，可扩展且易于使用。它以C语言实现，可在多种操作系统上运行，而无需进一步依赖。(该项目已在很大程度上被nng项目取代。鼓励用户使用nng)

通信模式，也称为“可伸缩性协议”，是构建分布式系统的基本模块。通过组合它们，可以创建大量的分布式应用程序。

以下是C中每种模式类型的示例：

Pipeline (A One-Way Pipe)
Request/Reply (I ask, you answer)
Pair (Two Way Radio)
Pub/Sub (Topics & Broadcast)
Survey (Everybody Votes)
Bus (Routing)

支持以下传输机制：

INPROC：在进程内传输（线程，模块等之间）
IPC：在一台机器上的进程之间传输
TCP：通过TCP进行网络传输
WS：TCP上的WebSockets

安装cmake

sudo apt-get install cmake

Linux下编译

解压nanomsg源码文件，进入目录，修改CMakeLists.txt

...
# User-defined options.option (NN_STATIC_LIB "Build static library instead of shared library." OFF)
option (NN_ENABLE_DOC "Enable building documentation." OFF)
option (NN_ENABLE_COVERAGE "Enable coverage reporting." OFF)
option (NN_ENABLE_GETADDRINFO_A "Enable/disable use of getaddrinfo_a in place of getaddrinfo." OFF)
option (NN_TESTS "Build and run nanomsg tests" OFF)
option (NN_TOOLS "Build nanomsg tools" OFF)
option (NN_ENABLE_NANOCAT "Enable building nanocat utility." ${NN_TOOLS})
set (NN_MAX_SOCKETS 512 CACHE STRING "max number of nanomsg sockets that can be created")#  Platform checks.
...

只编译生成静态库或者动态库，其他模块关掉。

执行：

./configure

然后：

make

在当前目录下生成：

libnanomsg.so
libnanomsg.so.5
libnanomsg.so.5.1.0

用file命令查看：

libnanomsg.so.5.1.0: ELF 64-bit LSB  shared object, x86-64, version 1 (SYSV), dy
namically linked, BuildID[sha1]=be8533fe8a4f4425f1f6067412b7306ea42e979e, not st
ripped

ARM下编译

解压nanomsg源码文件，进入目录，修改CMakeLists.txt

cmake_minimum_required (VERSION 2.8.12)
#添加配置
SET(CMAKE_C_COMPILER   arm-none-linux-gnueabi-gcc)
SET(CMAKE_CXX_COMPILER arm-none-linux-gnueabi-g++)
#完成配置
project (nanomsg C)
...
# User-defined options.option (NN_STATIC_LIB "Build static library instead of shared library." OFF)
option (NN_ENABLE_DOC "Enable building documentation." OFF)
option (NN_ENABLE_COVERAGE "Enable coverage reporting." OFF)
option (NN_ENABLE_GETADDRINFO_A "Enable/disable use of getaddrinfo_a in place of getaddrinfo." OFF)
option (NN_TESTS "Build and run nanomsg tests" OFF)
option (NN_TOOLS "Build nanomsg tools" OFF)
option (NN_ENABLE_NANOCAT "Enable building nanocat utility." ${NN_TOOLS})
set (NN_MAX_SOCKETS 512 CACHE STRING "max number of nanomsg sockets that can be created")#  Platform checks.
...

添加指定编译器。

只编译生成静态库或者动态库，其他模块关掉。

执行：

./configure

然后：

make

在当前目录下生成：

libnanomsg.so
libnanomsg.so.5
libnanomsg.so.5.1.0

用file命令查看：

libnanomsg.so.5.1.0: ELF 32-bit LSB  shared object, ARM, EABI5 version 1 (SYSV),dynamically linked, not stripped

C API

官方API：https://nanomsg.org/v1.1.5/nanomsg.html

创建一个SP套接字

nn_socket（3）
关闭一个SP套接字

nn_close（3）
设置套接字选项

nn_setsockopt（3）
检索套接字选项

nn_getsockopt（3）
将本地端点添加到套接字

nn_bind（3）
将远程端点添加到套接字

nn_connect（3）
从套接字删除端点

nn_shutdown（3）
发送消息

nn_send（3）
收到讯息

nn_recv（3）
nn_send的细粒度替代

nn_sendmsg（3）
nn_recv的细粒度替代

nn_recvmsg（3）
消息分配

nn_allocmsg（3） nn_reallocmsg（3） nn_freemsg（3）
消息控制数据的处理

nn_cmsg（3）
多路复用

nn_poll（3）
检索当前的errno

nn_errno（3）
将错误号转换为人类可读的字符串

nn_strerror（3）
查询nanomsg符号的名称和值

nn_symbol（3）
nanomsg符号的查询属性

nn_symbol_info（3）
查询套接字的统计信息

nn_get_statistic（3）
启动设备

nn_device（3）
通知所有套接字有关进程终止的信息

nn_term（3）
影响nanomsg工作的环境变量

nn_env（7）

nanomsg提供了以下可伸缩性协议：

一对一协议

nn_pair（7）
请求/回复协议

nn_reqrep（7）
发布/订阅协议

nn_pubsub（7）
调查协议

nn_survey（7）
管道协议

nn_pipeline（7）
消息总线协议

nn_bus（7）

nanomsg提供了以下传输机制：

流程中的运输

nn_inproc（7）
进程间运输

nn_ipc（7）
TCP传输

nn_tcp（7）
WebSocket传输

nn_ws（7）

库中安装了以下工具：

nanocat

nanocat(1)

Pipeline

管道（单向管道）

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此模式对于解决生产者/消费者问题（包括负载平衡）很有用。消息从推送侧流向推送侧。如果连接了多个对等方，则该模式将尝试公平分配。

pipeline.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <nanomsg/nn.h>
#include <nanomsg/pipeline.h>#define NODE0 "node0"
#define NODE1 "node1"void
fatal(const char *func)
{fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));exit(1);
}int
node0(const char *url)
{int sock;int rv;if ((sock = nn_socket(AF_SP, NN_PULL)) < 0) {fatal("nn_socket");}if ((rv = nn_bind(sock, url)) < 0) {fatal("nn_bind");}for (;;) {char *buf = NULL;int bytes;if ((bytes = nn_recv(sock, &buf, NN_MSG, 0)) < 0) {fatal("nn_recv");}printf("NODE0: RECEIVED \"%s\"\n", buf); nn_freemsg(buf);}
}int
node1(const char *url, const char *msg)
{int sz_msg = strlen(msg) + 1; // '\0' tooint sock;int rv;int bytes;if ((sock = nn_socket(AF_SP, NN_PUSH)) < 0) {fatal("nn_socket");}if ((rv = nn_connect(sock, url)) < 0) {fatal("nn_connect");}printf("NODE1: SENDING \"%s\"\n", msg);if ((bytes = nn_send(sock, msg, sz_msg, 0)) < 0) {fatal("nn_send");}sleep(1); // wait for messages to flush before shutting downreturn (nn_shutdown(sock, 0));
}int
main(const int argc, const char **argv)
{if ((argc > 1) && (strcmp(NODE0, argv[1]) == 0))return (node0(argv[2]));if ((argc > 2) && (strcmp(NODE1, argv[1]) == 0))return (node1(argv[2], argv[3]));fprintf(stderr, "Usage: pipeline %s|%s <URL> <ARG> ...'\n",NODE0, NODE1);return (1);
}

编译：

gcc pipeline.c -lnanomsg -o pipeline

执行：

./pipeline node0 ipc:///tmp/pipeline.ipc & node0=$! && sleep 1
./pipeline node1 ipc:///tmp/pipeline.ipc "Hello, World!"
./pipeline node1 ipc:///tmp/pipeline.ipc "Goodbye."
kill $node0

输出：

NODE1: SENDING "Hello, World!"
NODE0: RECEIVED "Hello, World!"
NODE1: SENDING "Goodbye."
NODE0: RECEIVED "Goodbye."

Request/Reply

请求/答复（我问，你回答）

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请求/答复用于同步通信，其中每个问题都用一个答案来回答，例如远程过程调用（RPC）。像Pipeline一样，它也可以执行负载平衡。这是套件中唯一可信赖的消息传递模式，因为如果请求与响应不匹配，它将自动重试。

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <nanomsg/nn.h>
#include <nanomsg/reqrep.h>#define NODE0 "node0"
#define NODE1 "node1"
#define DATE "DATE"void
fatal(const char *func)
{fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));exit(1);
}char *
date(void)
{time_t now = time(&now);struct tm *info = localtime(&now);char *text = asctime(info);text[strlen(text)-1] = '\0'; // remove '\n'return (text);
}int
node0(const char *url)
{int sz_date = strlen(DATE) + 1; // '\0' tooint sock;int rv;if ((sock = nn_socket(AF_SP, NN_REP)) < 0) {fatal("nn_socket");}if ((rv = nn_bind(sock, url)) < 0) {fatal("nn_bind");}for (;;) {char *buf = NULL;int bytes;if ((bytes = nn_recv(sock, &buf, NN_MSG, 0)) < 0) {fatal("nn_recv");}if ((bytes == (strlen(DATE) + 1)) && (strcmp(DATE, buf) == 0)) {printf("NODE0: RECEIVED DATE REQUEST\n");char *d = date();int sz_d = strlen(d) + 1; // '\0' tooprintf("NODE0: SENDING DATE %s\n", d);if ((bytes = nn_send(sock, d, sz_d, 0)) < 0) {fatal("nn_send");}}nn_freemsg(buf);}
}int
node1(const char *url)
{int sz_date = strlen(DATE) + 1; // '\0' toochar *buf = NULL;int bytes = -1;int sock;int rv;if ((sock = nn_socket(AF_SP, NN_REQ)) < 0) {fatal("nn_socket");}if ((rv = nn_connect (sock, url)) < 0) {fatal("nn_connect");}printf("NODE1: SENDING DATE REQUEST %s\n", DATE);if ((bytes = nn_send(sock, DATE, sz_date, 0)) < 0) {fatal("nn_send");}if ((bytes = nn_recv(sock, &buf, NN_MSG, 0)) < 0) {fatal("nn_recv");}printf("NODE1: RECEIVED DATE %s\n", buf);  nn_freemsg(buf);return (nn_shutdown(sock, 0));
}int
main(const int argc, const char **argv)
{if ((argc > 1) && (strcmp(NODE0, argv[1]) == 0))return (node0(argv[2]));if ((argc > 1) && (strcmp(NODE1, argv[1]) == 0))return (node1(argv[2]));fprintf(stderr, "Usage: reqrep %s|%s <URL> ...\n", NODE0, NODE1);return (1);
}

编译：

gcc reqrep.c -lnanomsg -o reqrep

执行：

./reqrep node0 ipc:///tmp/reqrep.ipc & node0=$! && sleep 1
./reqrep node1 ipc:///tmp/reqrep.ipc
kill $node0

输出：

NODE1: SENDING DATE REQUEST DATE
NODE0: RECEIVED DATE REQUEST
NODE0: SENDING DATE Sat Sep  7 17:39:01 2013
NODE1: RECEIVED DATE Sat Sep  7 17:39:01 2013

Pair

配对（双向广播）

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当存在一对一的对等关系时，将使用配对模式。一次只能将一个对等方连接到另一个对等方，但是两者都可以自由发言。

pair.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>#include <nanomsg/nn.h>
#include <nanomsg/pair.h>#define NODE0 "node0"
#define NODE1 "node1"void
fatal(const char *func)
{fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));exit(1);
}int
send_name(int sock, const char *name)
{printf("%s: SENDING \"%s\"\n", name, name);int sz_n = strlen(name) + 1; // '\0' tooreturn (nn_send(sock, name, sz_n, 0));
}int
recv_name(int sock, const char *name)
{char *buf = NULL;int result = nn_recv(sock, &buf, NN_MSG, 0);if (result > 0) {printf("%s: RECEIVED \"%s\"\n", name, buf); nn_freemsg(buf);}return (result);
}int
send_recv(int sock, const char *name)
{int to = 100;if (nn_setsockopt(sock, NN_SOL_SOCKET, NN_RCVTIMEO, &to,sizeof (to)) < 0) {fatal("nn_setsockopt");}for (;;) {recv_name(sock, name);sleep(1);send_name(sock, name);}
}int
node0(const char *url)
{int sock;if ((sock = nn_socket(AF_SP, NN_PAIR)) < 0) {fatal("nn_socket");}if (nn_bind(sock, url) < 0) {fatal("nn_bind");}return (send_recv(sock, NODE0));
}int
node1(const char *url)
{int sock;if ((sock = nn_socket(AF_SP, NN_PAIR)) < 0) {fatal("nn_socket");}if (nn_connect(sock, url) < 0) {fatal("nn_connect");}return (send_recv(sock, NODE1));
}int
main(const int argc, const char **argv)
{if ((argc > 1) && (strcmp(NODE0, argv[1]) == 0))return (node0(argv[2]));if ((argc > 1) && (strcmp(NODE1, argv[1]) == 0))return (node1(argv[2]));fprintf(stderr, "Usage: pair %s|%s <URL> <ARG> ...\n", NODE0, NODE1);return 1;
}

编译：

gcc pair.c -lnanomsg -o pair

执行：

./pair node0 ipc:///tmp/pair.ipc & node0=$!
./pair node1 ipc:///tmp/pair.ipc & node1=$!
sleep 3
kill $node0 $node1

输出：

node0: SENDING "node0"
node1: SENDING "node1"
node1: RECEIVED"node0"
node0: SENDING "node0"
node0: RECEIVED"node1"

Pub/Sub

发布/订阅（主题和广播）

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此模式用于允许单个广播者将消息发布给许多订阅者，订阅者可以选择限制它们接收的消息。

pubsub.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>#include <nanomsg/nn.h>
#include <nanomsg/pubsub.h>#define SERVER "server"
#define CLIENT "client"void
fatal(const char *func)
{fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));
}char *
date(void)
{time_t now = time(&now);struct tm *info = localtime(&now);char *text = asctime(info);text[strlen(text)-1] = '\0'; // remove '\n'return (text);
}int
server(const char *url)
{int sock;if ((sock = nn_socket(AF_SP, NN_PUB)) < 0) {fatal("nn_socket");}if (nn_bind(sock, url) < 0) {fatal("nn_bind");}for (;;) {char *d = date();int sz_d = strlen(d) + 1; // '\0' tooprintf("SERVER: PUBLISHING DATE %s\n", d);int bytes = nn_send(sock, d, sz_d, 0);if (bytes < 0) {fatal("nn_send");}sleep(1);}
}int
client(const char *url, const char *name)
{int sock;if ((sock = nn_socket(AF_SP, NN_SUB)) < 0) {fatal("nn_socket");}// subscribe to everything ("" means all topics)if (nn_setsockopt(sock, NN_SUB, NN_SUB_SUBSCRIBE, "", 0) < 0) {fatal("nn_setsockopt");}if (nn_connect(sock, url) < 0) {fatal("nn_connet");}for (;;) {char *buf = NULL;int bytes = nn_recv(sock, &buf, NN_MSG, 0);if (bytes < 0) {fatal("nn_recv");}printf("CLIENT (%s): RECEIVED %s\n", name, buf); nn_freemsg(buf);}
}int
main(const int argc, const char **argv)
{if ((argc >= 2) && (strcmp(SERVER, argv[1]) == 0))return (server(argv[2]));if ((argc >= 3) && (strcmp(CLIENT, argv[1]) == 0))return (client (argv[2], argv[3]));fprintf(stderr, "Usage: pubsub %s|%s <URL> <ARG> ...\n",SERVER, CLIENT);return 1;
}

编译：

gcc pubsub.c -lnanomsg -o pubsub

执行：

./pubsub server ipc:///tmp/pubsub.ipc & server=$! && sleep 1
./pubsub client ipc:///tmp/pubsub.ipc client0 & client0=$!
./pubsub client ipc:///tmp/pubsub.ipc client1 & client1=$!
./pubsub client ipc:///tmp/pubsub.ipc client2 & client2=$!
sleep 5
kill $server $client0 $client1 $client2

输出：

SERVER: PUBLISHING DATE Sat Sep  7 17:40:11 2013
SERVER: PUBLISHING DATE Sat Sep  7 17:40:12 2013
SERVER: PUBLISHING DATE Sat Sep  7 17:40:13 2013
CLIENT (client2): RECEIVED Sat Sep  7 17:40:13 2013
CLIENT (client0): RECEIVED Sat Sep  7 17:40:13 2013
CLIENT (client1): RECEIVED Sat Sep  7 17:40:13 2013
SERVER: PUBLISHING DATE Sat Sep  7 17:40:14 2013
CLIENT (client2): RECEIVED Sat Sep  7 17:40:14 2013
CLIENT (client1): RECEIVED Sat Sep  7 17:40:14 2013
CLIENT (client0): RECEIVED Sat Sep  7 17:40:14 2013
SERVER: PUBLISHING DATE Sat Sep  7 17:40:15 2013
CLIENT (client1): RECEIVED Sat Sep  7 17:40:15 2013
CLIENT (client2): RECEIVED Sat Sep  7 17:40:15 2013
CLIENT (client0): RECEIVED Sat Sep  7 17:40:15 2013
SERVER: PUBLISHING DATE Sat Sep  7 17:40:16 2013
CLIENT (client1): RECEIVED Sat Sep  7 17:40:16 2013
CLIENT (client2): RECEIVED Sat Sep  7 17:40:16 2013
CLIENT (client0): RECEIVED Sat Sep  7 17:40:16 2013

Survey

调查（所有人投票）

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用于发送定时调查，调查被单独返回直到调查到期。此模式对于服务发现和投票算法很有用。

survey.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>#include <nanomsg/nn.h>
#include <nanomsg/survey.h>#define SERVER "server"
#define CLIENT "client"
#define DATE   "DATE"void
fatal(const char *func)
{fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));exit(1);
}char *
date(void)
{time_t now = time(&now);struct tm *info = localtime(&now);char *text = asctime(info);text[strlen(text)-1] = '\0'; // remove '\n'return (text);
}int
server(const char *url)
{int sock;if ((sock = nn_socket (AF_SP, NN_SURVEYOR)) < 0) {fatal("nn_socket");}if (nn_bind(sock, url)  < 0) {fatal("nn_bind");}for (;;) {printf("SERVER: SENDING DATE SURVEY REQUEST\n");int bytes = nn_send(sock, DATE, strlen(DATE) + 1, 0);if (bytes < 0) {fatal("nn_send");}for (;;) {char *buf = NULL;int bytes = nn_recv(sock, &buf, NN_MSG, 0);if (bytes < 0) {if (nn_errno() == ETIMEDOUT) {break;}fatal("nn_recv");}printf("SERVER: RECEIVED \"%s\" SURVEY RESPONSE\n",buf); nn_freemsg(buf);}printf("SERVER: SURVEY COMPLETE\n");sleep(1); // Start another survey in a second}
}int
client(const char *url, const char *name)
{int sock;if ((sock = nn_socket(AF_SP, NN_RESPONDENT)) < 0) {fatal("nn_socket");}if (nn_connect (sock, url) < 0) {fatal("nn_connect");}for (;;) {char *buf = NULL;int bytes = nn_recv(sock, &buf, NN_MSG, 0);if (bytes >= 0) {printf("CLIENT (%s): RECEIVED \"%s\" SURVEY REQUEST\n",name, buf); nn_freemsg(buf);char *d = date();int sz_d = strlen(d) + 1; // '\0' tooprintf("CLIENT (%s): SENDING DATE SURVEY RESPONSE\n",name);if (nn_send(sock, d, sz_d, 0) < 0) {fatal("nn_send");}}}
}int
main(const int argc, const char **argv)
{if ((argc >= 2) && (strcmp(SERVER, argv[1]) == 0))return (server(argv[2]));if ((argc >= 3) && (strcmp(CLIENT, argv[1]) == 0))return (client(argv[2], argv[3]));fprintf(stderr, "Usage: survey %s|%s <URL> <ARG> ...\n",SERVER, CLIENT);return 1;
}

编译：

gcc survey.c -lnanomosg -o survey

执行：

./survey server ipc:///tmp/survey.ipc & server=$!
./survey client ipc:///tmp/survey.ipc client0 & client0=$!
./survey client ipc:///tmp/survey.ipc client1 & client1=$!
./survey client ipc:///tmp/survey.ipc client2 & client2=$!
sleep 4
kill $server $client0 $client1 $client2

输出：

SERVER: SENDING DATE SURVEY REQUEST
SERVER: SURVEY COMPLETE
SERVER: SENDING DATE SURVEY REQUEST
CLIENT (client2): RECEIVED "DATE" SURVEY REQUEST
CLIENT (client1): RECEIVED "DATE" SURVEY REQUEST
CLIENT (client0): RECEIVED "DATE" SURVEY REQUEST
CLIENT (client1): SENDING DATE SURVEY RESPONSE
CLIENT (client0): SENDING DATE SURVEY RESPONSE
CLIENT (client2): SENDING DATE SURVEY RESPONSE
SERVER: RECEIVED "Mon Jan  8 13:10:43 2018" SURVEY RESPONSE
SERVER: RECEIVED "Mon Jan  8 13:10:43 2018" SURVEY RESPONSE
SERVER: RECEIVED "Mon Jan  8 13:10:43 2018" SURVEY RESPONSE
SERVER: SURVEY COMPLETE

Bus

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总线协议对于路由应用程序或构建完全互连的网状网络很有用。在这种模式下，消息被发送到每个直接连接的对等方。

bus.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>#include <nanomsg/nn.h>
#include <nanomsg/bus.h>void
fatal(const char *func)
{fprintf(stderr, "%s: %s\n", func, nn_strerror(nn_errno()));exit(1);
}int
node(const int argc, const char **argv)
{int sock;if ((sock = nn_socket (AF_SP, NN_BUS)) < 0) {fatal("nn_socket");}if (nn_bind(sock, argv[2]) < 0) {fatal("nn_bind");}sleep(1); // wait for peers to bindif (argc >= 3) {for (int x = 3; x < argc; x++) {if (nn_connect(sock, argv[x]) < 0) {fatal("nn_connect");}}}sleep(1); // wait for connectionsint to = 100;if (nn_setsockopt(sock, NN_SOL_SOCKET, NN_RCVTIMEO, &to,sizeof (to)) < 0) {fatal("nn_setsockopt");}// SENDint sz_n = strlen(argv[1]) + 1; // '\0' tooprintf("%s: SENDING '%s' ONTO BUS\n", argv[1], argv[1]);if (nn_send(sock, argv[1], sz_n, 0) < 0) {fatal("nn_send");}// RECVfor (;;) {char *buf = NULL;int recv = nn_recv(sock, &buf, NN_MSG, 0);if (recv >= 0) {printf("%s: RECEIVED '%s' FROM BUS\n", argv[1], buf); nn_freemsg(buf);}}return (nn_shutdown(sock, 0));
}int
main(int argc, const char **argv)
{if (argc >= 3) {return (node(argc, argv));}fprintf(stderr, "Usage: bus <NODE_NAME> <URL> <URL> ...\n");return 1;
}

Compilation

gcc bus.c -lnanomsg -o bus

Execution

./bus node0 ipc:///tmp/node0.ipc ipc:///tmp/node1.ipc ipc:///tmp/node2.ipc & node0=$!
./bus node1 ipc:///tmp/node1.ipc ipc:///tmp/node2.ipc ipc:///tmp/node3.ipc & node1=$!
./bus node2 ipc:///tmp/node2.ipc ipc:///tmp/node3.ipc & node2=$!
./bus node3 ipc:///tmp/node3.ipc ipc:///tmp/node0.ipc & node3=$!
sleep 5
kill $node0 $node1 $node2 $node3

Output

node0: SENDING 'node0' ONTO BUS
node1: SENDING 'node1' ONTO BUS
node2: SENDING 'node2' ONTO BUS
node3: SENDING 'node3' ONTO BUS
node0: RECEIVED 'node1' FROM BUS
node0: RECEIVED 'node2' FROM BUS
node0: RECEIVED 'node3' FROM BUS
node1: RECEIVED 'node0' FROM BUS
node1: RECEIVED 'node2' FROM BUS
node1: RECEIVED 'node3' FROM BUS
node2: RECEIVED 'node0' FROM BUS
node2: RECEIVED 'node1' FROM BUS
node2: RECEIVED 'node3' FROM BUS
node3: RECEIVED 'node0' FROM BUS
node3: RECEIVED 'node1' FROM BUS
node3: RECEIVED 'node2' FROM BUS