标签：centos 6 manual from ber hello comm tip 模式 world
1)netcat(nc)是一个简单而有用的工具，被誉为网络安全界的“瑞士军刀”，不仅可以通过使用TCP或UDP协议的网络连接读写数据，同时还是一个功能强大的网络调试和探测工具，能够建立你需要的几乎所有类型的网络连接。
2)在Linux终端窗口可以直接使用yum工具进行安装：
[root@master01 spark]# yum install nc.x86_64
3)安装完毕后，在终端模式下运行nc -help查看命令是否正常安装
[hadoop@master01 spark]$ nc -help usage: nc [-46DdhklnrStUuvzC] [-i interval] [-p source_port] [-s source_ip_address] [-T ToS] [-w timeout] [-X proxy_version] [-x proxy_address[:port]] [hostname] [port[s]] Command Summary: -4 Use IPv4 -6 Use IPv6 -D Enable the debug socket option -d Detach from stdin -h This help text -i secs Delay interval for lines sent, ports scanned -k Keep inbound sockets open for multiple connects -l Listen mode, for inbound connects -n Suppress name/port resolutions -p port Specify local port for remote connects -r Randomize remote ports -S Enable the TCP MD5 signature option -s addr Local source address -T ToS Set IP Type of Service -C Send CRLF as line-ending -t Answer TELNET negotiation -U Use UNIX domain socket -u UDP mode -v Verbose -w secs Timeout for connects and final net reads -X proto Proxy protocol: "4", "5" (SOCKS) or "connect" -x addr[:port] Specify proxy address and port -z Zero-I/O mode [used for scanning] Port numbers can be individual or ranges: lo-hi [inclusive]
OK，安装正常。下面我们就可以使用nc -l 9999 来监听端口，并发送数据；
[hadoop@master01 spark]$ nc -lk 8888 Hello world! How are you? Goodbye!
在我的CentOS 6.4(64-bit) 环境中执行 nc -l 9999 监听命令遇到protocol not available。
[hadoop@master01 spark]$ nc -l 9999 nc: Protocol not available
解决方法如下：
# Removes the old package yum erase nc # Manually downloads the working package from the Official Repository wget http://vault.centos.org/6.6/os/x86_64/Packages/nc-1.84-22.el6.x86_64.rpm # Installs the package rpm -iUv nc-1.84-22.el6.x86_64.rpm
另：本系统为64位操作系统，若读者使用的是i386 (32-bit)，可以使用如下链接：
wget http://vault.centos.org/6.6/os/i386/Packages/nc-1.84-22.el6.i686.rpm
标签：centos 6 manual from ber hello comm tip 模式 world
原文地址：https://www.cnblogs.com/bigdata-stone/p/9376376.html
