UUCP method using Unix system

Many people don't know what UUCP is doing in Unix. In fact, UUCP is not as complicated as everyone thinks. It is very convenient to use. Xiaobian will explain the use of Unix in detail. UUCP method.

UUCP network system is the most widely used practical system, in which two reasons:

First, UUCP is the only standard variety of Unix operating system versions are available Network System

Second, UUCP is the cheapest network system. Only one cable is needed to connect the two systems, and then 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 UUCP command for Unix operating system

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

The source_file is usually a file of the Unix operating system, but it does not have to be that the destination_file is usually a file or directory of another system. The format of the destination_file is specified as:

uucp provides the system administrator with an option to restrict the transfer of uucp files to and from the Unix operating system to the /usr/spool/uucppublic directory structure. If uucp is told to store the transferred file in another directory, the system will send back one:

uucp allows the simplified symbol ~ instead of /usr/spool/uucppublic/. Such as:

Sometimes uucp can be used to copy files from another system to the Unix operating system, as long as the file to be passed to the system is specified as the source file with system! File can be, for example:

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

2 uux commands

The uux command can be used on another Unix operating system. Executing commands on this feature is called “remote command limp”. The most common use of uux is to send mail between systems to execute uux. The typical uux request is as follows:

This command arranges the file listing format and then connects to the printer of the Unix operating system remote1. The .uux option printed on pr1 “-” enables uux to establish the standard input device of this command as a standard input device for remote commands. Uux print files are commonly used when only one of several systems is connected to a printer.

Of course, remote command entertainment must be strictly limited to protect 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 the /etc/passwd file to the system outside. Generally, only a few commands allow Execution.rmail is a restricted mail program, often one of the commands that are allowed to be executed by uux. The netnews pseudo-command, which also allows rnews to be restricted, is executed on systems running netnews and also allows lp to run on systems that provide printing devices.

3 uucico Programs

The uucp and uux commands do not actually call another system and transfer files and execute commands. Instead, they queue the user's request and start the uucico program. uucico Complete the actual communication work. It calls other systems, logs in, and transfers data can be files or request remote command execution. If the phone line is busy, or other Unix operating systems have been shut down, the transfer request remains in the queue, and the subsequent functional operations of uucico are usually cron completions that will send these transfer requests.

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

4 uuxqt program

When another system's uucico calls the Unix operating system to request remote command execution, the system's uucico queues the request and starts the uuxqt program before exiting. Execute a remote command request.

The above is the introduction of the UUCP function in the Unix system. Here you can copy files from one host to another, and remote host operations.