Contains instructions for running commands that require the resources of a remote system.
The execute (X.*) files of the Basic Networking Utilities (BNU) contain instructions for running commands that require the resources of a remote system. They are created by the uux command.
The full path name of a uux command execute file is a form of the following:
/var/spool/uucp/SystemName/X.RemoteSystemNxxxx
where the SystemName directory is named for the local computer and the RemoteSystem directory is named for the remote system. The N character represents the grade of the work, and the xxxx notation is the four-digit hexadecimal transfer-sequence number; for example, X.zeusN2121.
Note: The grade of the work specifies when the file is to be transmitted during a particular connection. The grade notation is a single number (0-9) or letter (A-Z, a-z). Lower sequence characters cause the file to be transmitted earlier in the connection than do higher sequence characters. The number 0 is the highest grade, signifying the earliest transmittal; z is the lowest grade, specifying the latest transmittal. The default grade is N.
An execute file consists of several lines, each with an identification character and one or more entries:
| U UserName SystemName | Specifies the login name of the user issuing the uux command and the name of the system that issued the command. |
| R UserName | Specifies the login ID of the user requesting the remote command execution. |
| F FileName | Contains the names of the files required to execute the specified command
on the remote system. The FileName parameter can be either
the complete path name of the file, including the unique transmission name
assigned by the BNU program, or simply the transmission name without any path
information.
The required file line can contain zero or more file names. The uuxqt daemon checks for the existence of all listed files before running the specified command. |
| C CommandString | Gives the command string that the user requests to be run on the
specified system. The BNU program checks the /etc/uucp/Permissions file on the designated
computer to see whether the login ID can run the command on that
system.
All required files go to the execute file directory, usually /var/spool/uucp/.Xqtdir. After execution, the standard output is sent to the requested location. |
uux - "diff /home/amy/out hera!/home/amy/out2 > ~/DF"
The command in this example invokes the uux command to run a diff command on the local system, comparing the /home/amy/out file with the /home/amy/out2 file, which is stored on remote system hera. The output of the comparison is placed in the DF file in the public directory on the local system.
The preceding command produces the /var/spool/uucp/hera/X.zeusN212F execute file, which contains the following information:
The user line identifies the user amy on the system zeus. The error-status line indicates that amy will receive a failure status message if the diff command fails to execute. The requestor is amy, and the file required to execute the command is the following data file:
U amy zeus # return status on failure Z # return address for status or input return R amy F /var/spool/uucp/hera/D.herale954fd out2 O ~/DF zeus C diff /home/amy/out out2 /var/spool/uucp/hera/D.herale954fd out2
The output of the command is to be written to the public directory on the system zeus with the file name DF. (The ~ (tilde) is the shorthand way of specifying the public directory.) The final line is the command string that the user amy entered with the uux command.
U uucp hera # don't return status on failure N # return address for status or input return R uucp F D.hera5eb7f7b I D.hera5eb7f7b C rmail amy
This indicates that user uucp on system hera is sending mail to user amy, who is also working on system hera.
These files are part of the Basic Networking Utilities Program (BNU) in BOS Extensions 1.
| /etc/uucp/Permissions | Describes access permissions for remote systems. |
| /etc/uucp/Systems | Describes accessible remote systems. |
| /var/spool/uucp/SystemName directory | Contains BNU command, data, and execute files. |
| /var/spool/uucp/SystemName/C.* | Contains instructions for transfers. |
| /var/spool/uucp/.Xqtdir directory | Contains lists of commands that remote systems are permitted to execute. |
| /var/spool/uucppublic/* directory | Contains transferred files. |
The diff command, uux command.
The uuxqt daemon.
BNU File and Directory Structure, BNU Daemons, and BNU Maintenance Commands in AIX 5L Version 5.1 System Management Guide: Communications and Networks.