这里有两台主机，其中
192.168.1.4上安装的是Linux Mint 18.2 Sonya系统。主机名是linuxidccom，用户名是linuxidc。
192.168.1.25上安装的是Ubuntu Server 16.04.3 LT系统。主机名是ubuntu，用户名是linuxidc。
当在192.168.1.25上输入命令apt的时候这样的：
linuxidc@ubuntu:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 08:00:27:5e:65:ca brd ff:ff:ff:ff:ff:ff inet 192.168.1.25/24 brd 192.168.1.255 scope global enp0s3 valid_lft forever preferred_lft forever inet6 fe80::a00:27ff:fe5e:65ca/64 scope link valid_lft forever preferred_lft forever linuxidc@ubuntu:~$ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 16.04.3 LTS Release: 16.04 Codename: xenial linuxidc@ubuntu:~$ apt apt 1.2.24 (amd64) Usage: apt [options] command apt is a commandline package manager and provides commands for searching and managing as well as querying information about packages. It provides the same functionality as the specialized APT tools, like apt-get and apt-cache, but enables options more suitable for interactive use by default. Most used commands: list - list packages based on package names search - search in package descriptions show - show package details install - install packages remove - remove packages autoremove - Remove automatically all unused packages update - update list of available packages upgrade - upgrade the system by installing/upgrading packages full-upgrade - upgrade the system by removing/installing/upgrading packages edit-sources - edit the source information file See apt(8) for more information about the available commands. Configuration options and syntax is detailed in apt.conf(5). Information about how to configure sources can be found in sources.list(5). Package and version choices can be expressed via apt_preferences(5). Security details are available in apt-secure(8). This APT has Super Cow Powers. linuxidc@ubuntu:~$当在192.168.1.4上输入命令apt的时候却是这样的：
linuxidc@linuxidccom ~ $ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: wlp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 9c:b6:d0:dd:fc:f7 brd ff:ff:ff:ff:ff:ff inet 192.168.1.4/24 brd 192.168.1.255 scope global dynamic wlp2s0 valid_lft 246699sec preferred_lft 246699sec inet6 fe80::a0fd:f518:e91a:dde0/64 scope link valid_lft forever preferred_lft forever linuxidc@linuxidccom ~ $ lsb_release -a No LSB modules are available. Distributor ID: LinuxMint Description: Linux Mint 18.2 Sonya Release: 18.2 Codename: sonya linuxidc@linuxidccom ~ $ apt apt Usage: apt command [options] apt help command [options] Commands: add-repository - Add entries to apt sources.list autoclean - Erase old downloaded archive files autoremove - Remove automatically all unused packages build - Build binary or source packages from sources build-dep - Configure build-dependencies for source packages changelog - View a package's changelog check - Verify that there are no broken dependencies clean - Erase downloaded archive files contains - List packages containing a file content - List files contained in a package deb - Install a .deb package depends - Show raw dependency information for a package dist-upgrade - Upgrade the system by removing/installing/upgrading packages download - Download the .deb file for a package edit-sources - Edit /etc/apt/sources.list with your preferred text editor dselect-upgrade - Follow dselect selections full-upgrade - Same as 'dist-upgrade' held - List all held packages help - Show help for a command hold - Hold a package install - Install/upgrade packages list - List packages based on package names policy - Show policy settings purge - Remove packages and their configuration files recommends - List missing recommended packages for a particular package rdepends - Show reverse dependency information for a package reinstall - Download and (possibly) reinstall a currently installed package remove - Remove packages search - Search for a package by name and/or expression show - Display detailed information about a package showhold - Same as 'held' source - Download source archives sources - Same as 'edit-sources' unhold - Unhold a package update - Download lists of new/upgradable packages upgrade - Perform a safe upgrade version - Show the installed version of a package linuxidc@linuxidccom ~ $ apt help install "apt install " is equivalent to "sudo /usr/bin/apt install " linuxidc@linuxidccom ~ $ apt help add-repository "apt add-repository " is equivalent to "sudo add-apt-repository " linuxidc@linuxidccom ~ $ apt help purge "apt purge " is equivalent to "sudo /usr/bin/apt purge " linuxidc@linuxidccom ~ $有没有一种办法让Ubuntu Server 16.04.3 LT系统也拥有Linux Mint 18.2 Sonya那样的apt功能呢？
2、解决方案让我我们先查找一下apt命令的出处吧。