1 问题
[root@cm ~]# nc -l 9000
-bash: nc: command not found
提示： 无法使用这个nc命令。因为没有配置这个命令。
2 解决办法
输入命令：
[root@hadoop1 ~]# yum install -y nc
运行结果：
[root@cm ~]# yum install -y nc
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.163.com
* extras: centos.ustc.edu.cn
* updates: centos.ustc.edu.cn
Resolving Dependencies
--> Running transaction check
---> Package nmap-ncat.x86_64 2:6.40-16.el7 will be installed
--> Processing Dependency: libpcap.so.1()(64bit) for package: 2:nmap-ncat-6.40-16.el7.x86_64
--> Running transaction check
---> Package libpcap.x86_64 14:1.5.3-11.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
===================================================================================================================================
Package Arch Version Repository Size
===================================================================================================================================
Installing:
nmap-ncat x86_64 2:6.40-16.el7 base 206 k
Installing for dependencies:
libpcap x86_64 14:1.5.3-11.el7 base 138 k
Transaction Summary
===================================================================================================================================
Install 1 Package (+1 Dependent package)
Total download size: 344 k
Installed size: 740 k
Downloading packages:
warning: /var/cache/yum/x86_64/7/base/packages/nmap-ncat-6.40-16.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Public key for nmap-ncat-6.40-16.el7.x86_64.rpm is not installed
(1/2): nmap-ncat-6.40-16.el7.x86_64.rpm | 206 kB 00:00:00
(2/2): libpcap-1.5.3-11.el7.x86_64.rpm | 138 kB 00:00:00
-----------------------------------------------------------------------------------------------------------------------------------
Total 517 kB/s | 344 kB 00:00:00
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Importing GPG key 0xF4A80EB5:
Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>"
Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5
Package : centos-release-7-4.1708.el7.centos.x86_64 (@anaconda)
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : 14:libpcap-1.5.3-11.el7.x86_64 1/2
Installing : 2:nmap-ncat-6.40-16.el7.x86_64 2/2
Verifying : 14:libpcap-1.5.3-11.el7.x86_64 1/2
Verifying : 2:nmap-ncat-6.40-16.el7.x86_64 2/2
Installed:
nmap-ncat.x86_64 2:6.40-16.el7
Dependency Installed:
libpcap.x86_64 14:1.5.3-11.el7
Complete!