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This article introduces the relevant knowledge of "how to use the network practical system UUCP in the Unix system". In the operation of the actual case, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

UUCP is the most widely used network utility system for two reasons:

First, UUCP is the only standard network system available in various versions of the Unix operating system

Second, UUCP is the cheapest network system. Only one cable is needed to connect the two systems, and then the UUCP can be established. If you need to transfer data between two systems hundreds or thousands of kilometers apart, you need two modems with dialing capabilities.

1 Unix operating system UUCP command

One of the UUCP commands is uucp, which is used for file transfer between the two systems. The format of the uucp command is similar to that of the cp command, except that uucp allows users to copy files between systems. The general format of the command is as follows:

Source_file is usually a file of the Unix operating system, but it doesn't have to be. Destination_file is usually a file or directory of another system. Specify the format of destination_file as:

Uucp gives system administrators an option to restrict the transfer of uucp files to and from the Unix operating system to the / usr/spool/uucppublic directory structure. If you tell uucp to store the transferred file in another directory, the system will send back one:

Uucp allows / usr/spool/uucppublic/ to be replaced by a simplified symbol ~. Such as:

Sometimes you can use uucp to copy files from another system to the Unix operating system, as long as the files to be passed into this system are specified as source files using system! File is fine, such as:

If the directory for file transfer is restricted on the remote machine, the previous command cannot be copied to the file. The safest way to copy files to this system is to transfer files through the uucppublic directory on both systems:

2 uux command

The uux command can be used to execute commands on another Unix operating system, a feature known as "remote command lines". The most common use of uux is to send mail between systems. Mail executes uux. A typical uux request is as follows:

This command formats the file listing and then connects it to the printer pr1 of the Unix operating system remote1 to print out the .uux option "-" causes uux to establish the standard input device of this command as the standard input device of remote commands. Uux is often used to print files when only one of several systems has a printer connected.

Of course, remote command hospitality must be strictly restricted to protect the security of the system. For example, this system should not allow users on other systems to run the following commands:

This command will cause the Unix operating system to transfer / etc/passwd files to the system outside. In general, only a few commands are allowed to execute .rmail is a restricted mail program, often one of the commands allowed to be executed through uux. It also allows rnews restricted netnews pseudo-offline commands to be executed on the system running netnews, and also allows lp to run on systems that provide printing devices.

3 uucico program

Instead of actually invoking another system and transferring files and executing commands, the uucp and uux commands queue the user's request and start the uucico program .uucico to complete the actual communication. It invokes other systems, logs in, and transfers data that can be files or request remote command execution. If the phone line is busy, or other Unix operating systems are turned off, the transmission requests remain in the queue, and the subsequent function of the uucico is usually that the cron completes to send these transmission requests.

Uucico completes the sending and receiving of data. In the / etc/passwd file of this system, the uucico login of other systems enters the entry entry of this system, and the default shell specified in this entry is uucico. Therefore, when other systems call this system, they talk to uucico directly.

4 uuxqt program

When the uucico of another system calls the Unix operating system to request remote command execution, the uucico of the system queues the request and starts the uuxqt program to execute the remote command request before exiting.

This is the introduction of the UUCP function in the Unix system, through which you can copy files from one host to another and operate on a remote host.

This is the end of the introduction of "how the Unix system uses the network utility system UUCP". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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