uux(1)

NAME

uux — UNIX system to UNIX system command execution

SYNOPSIS

uux [options] command-string

DESCRIPTION

uux gathers zero or more files from various systems, executes a command on a specified system, then sends standard output to a file on a specified system. Note that, for security reasons, many installations limit the list of commands executable on behalf of an incoming request from uux. Many sites will permit little more than the receipt of mail (see mail(1), mailx(1), and elm(1)) via uux.

The command-string is made up of one or more arguments that look like a shell command line, except that the command and file names may be prefixed by system-name!. A null system-name is interpreted as the local system.

File names can be one of the following:

A full path name;
A path name preceded by ~xxx where xxx is a login name on the specified system and is replaced by that user's login directory. Note that if an invalid login is specified, the default will be to the public directory (/var/spool/uucppublic);
A path name preceded by ~/destination where destination is appended to /var/spool/uucppublic.
A simple file name (which is prefixed by the current directory). See uucp(1) for details.

For example, the command

uux "!diff usg!/usr/dan/file1 pwba!/a4/dan/file2 > !~/dan/file.diff" 

gets files file1 and file2 from machines usg and pwba, and executes a diff(1) command, placing the results in file.diff in the local directory /var/spool/uucppublic.

Any special shell characters such as <, >, ;, or | should be quoted, either by quoting the entire command-string, or quoting the special characters as individual arguments.

uux attempts to get all files to the execution system. For files that are output files, the file name must be escaped using parentheses. For example, the command

uux a!cut -f1 b!/usr/file \(c!/usr/file\) 

gets /usr/file from system b and sends it to system a, performs a cut command on the file, and sends the result of the cut command to system c.

uux notifies you if the requested command on the remote system was disallowed. The list of commands allowed is specified in the Permissions file in /etc/uucp. The response comes by remote mail from the remote machine.

uux recognizes the following options:

-: The standard input to uux is made the standard input to the command-string.
-aname: Use name as the user identification replacing the initiator user-ID (notification is returned to the user).
-b: Return whatever standard input was provided to the uux command if the exit status is non-zero.
-c: Do not copy the local file to the spool directory for transfer to the remote machine (default).
-C: Force the copy of local files to the spool directory for transfer.
-ggrade: grade is a single letter/number; lower ASCII sequence characters cause the job to be transmitted earlier during a particular conversation.
-j: Output the jobid (the job identification ASCII string) on the standard output. This job identification can be used by uustat to obtain the status or terminate a job (see uustat(1)).
-n: Do not notify the user if the command fails.
-r: Do not start the file transfer, just queue the job.
-sfile: Report status of the transfer in file.
-xdebug_level: Produce debugging output on standard output. The debug_level is a number between 0 and 9. The higher the number, the more detailed the information returned.
-z: Send success notification to user.

WARNINGS

Only the first command of a shell pipeline can have a system-name!. All other commands are executed on the system of the first command.

The use of the shell metacharacter * will probably not do what you want it to do. The shell tokens << and >> are not implemented.

The execution of commands on remote systems takes place in an execution directory known to the UUCP subsystem. All files required for the execution are put into this directory unless they already reside on that machine. Therefore, the simple file name (without path or machine reference) must be unique within the uux request. The following command does not work:

uux "a!diff b!/usr/dan/xyz c!/usr/dan/xyz > !xyz.diff" 

but the command:

uux "a!diff a!/usr/dan/xyz c!/usr/dan/xyz > !xyz.diff" 

works (if diff is a permitted command).

Protected files and files that are in protected directories that are owned by the requester can be sent in commands using uux. However, if the requester is root, and the directory is not searchable by other, the request fails.

FILES

/etc/uucp: configuration files
/var/uucp: log and error files
/var/spool/uucp: spool directories
/var/spool/locks: lock files
/var/spool/uucppublic: public directory

STANDARDS CONFORMANCE

uux: SVID2, SVID3, XPG2, XPG3, XPG4

uux(1)

Technical documentation

» Table of Contents

» Index