centos7 arp: command not found

如果在 CentOS 7 中输入 `arp` 命令时提示 `command not found`，可能是因为系统中没有安装 `net-tools` 包，`arp` 命令属于 `net-tools` 包的一部分。

可以通过以下命令来安装 `net-tools` 包：

sudo yum install net-tools

安装完成后，再次输入 `arp -a` 命令即可查看 ARP 缓存表。

相关问题

centos7 sudo: psql: command not found

The error "sudo: psql: command not found" indicates that the "psql" command is not available on your system or it is not in the system's PATH.

To install the PostgreSQL client tools on CentOS 7, you can run the following command:

sudo yum install postgresql

Once the installation is complete, you should be able to run the "psql" command with sudo privileges. If you still encounter the same error, you may need to add the PostgreSQL client tools directory to your system PATH.

On CentOS 7, you can do this by adding the following line to the end of your `~/.bashrc` file:

export PATH=$PATH:/usr/pgsql-<version>/bin

Replace `<version>` with the version number of PostgreSQL that you have installed. After saving the file, run `source ~/.bashrc` to reload the PATH configuration.

CentOS7 -bash: wget: command not found

在CentOS7中，当出现-bash: wget: command not found的错误时，可能是由于系统缺少wget这个下载命令器所致。你可以使用以下命令来安装wget：

yum install wget -y

这条命令将会通过yum包管理器来安装wget，并且使用了-y选项来跳过任何确认提示。执行完上述命令后，你应该可以正常使用wget命令了。