UID-User identification number, which uniquely corresponds to the user name. The Uid of superuser root in LINUX is 0. If you want the system to display your user name, UID, group name, GID and the names of other groups to which you belong, you can use the ID command. Usermod -u is generally used to modify UID.

Linux is a Unix-like operating system, which can be used and distributed for free. It is a multi-user, multi-task, multi-thread and multi-CPU operating system based on POSIX and Unix. It can run major Unix tools, applications and network protocols. It supports 32-bit and 64-bit hardware. Linux inherits the network-centric design idea of Unix and is a multi-user network operating system with stable performance.

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Advantages:

1, Linux consists of many microkernels, and its source code is completely open source;

2.Linux inherits the characteristics of Unix and has very powerful network functions. It supports all Internet protocols, including TCP/IPv4? TCP/IPv6 and link layer topology programs, etc. , you can use the network characteristics of Unix to develop new protocol stacks;

3. The tool chain of 3.Linux system is complete, and the appropriate development environment can be configured through simple operation, which can simplify the development process, reduce the obstacles of simulation tools in development, and make the system highly portable;

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