UUX(1)                     POSIX Programmer's Manual                    UUX(1)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NAME
       uux -- remote command execution

SYNOPSIS
       uux [[-jnp]] command-string

DESCRIPTION
       The uux utility shall gather zero or more files from various systems,
       execute a shell pipeline (see Section 2.9, Shell Commands) on a
       specified system, and then send the standard output of the command to a
       file on a specified system. Only the first command of a pipeline can
       have a system-name!  prefix. All other commands in the pipeline shall
       be executed on the system of the first command.

       The following restrictions are applicable to the shell pipeline
       processed by uux:

        *  In gathering files from different systems, pathname expansion shall
           not be performed by uux.  Thus, a request such as:


               uux "c99 remsys!~/*.c"

           would attempt to copy the file named literally *.c to the local
           system.

        *  The redirection operators "">>>>"", ""<<<<"", "">>||"", and "">>&&"" shall not be
           accepted. Any use of these redirection operators shall cause this
           utility to write an error message describing the problem and exit
           with a non-zero exit status.

        *  The reserved word !!  cannot be used at the head of the pipeline to
           modify the exit status.  (See the command-string operand
           description below.)

        *  Alias substitution shall not be performed.

       A filename can be specified as for uucp; it can be an absolute
       pathname, a pathname preceded by ~name (which is replaced by the
       corresponding login directory), a pathname specified as ~/dest (dest is
       prefixed by the public directory called PUBDIR; the actual location of
       PUBDIR is implementation-defined), or a simple filename (which is
       prefixed by uux with the current directory). See uucp for the details.

       The execution of commands on remote systems shall take place in an
       execution directory known to the uucp system. All files required for
       the execution shall be put into this directory unless they already
       reside on that machine. Therefore, the application shall ensure that
       non-local filenames (without path or machine reference) are unique
       within the uux request.

       The uux utility shall attempt to get all files to the execution system.
       For files that are output files, the application shall ensure that the
       filename is escaped using parentheses.

       The remote system shall notify the user by mail if the requested
       command on the remote system was disallowed or the files were not
       accessible. This notification can be turned off by the -n option.

       Typical implementations of this utility require a communications line
       configured to use the Base Definitions volume of POSIX.1-2017, Chapter
       11, General Terminal Interface, but other communications means may be
       used. On systems where there are no available communications means
       (either temporarily or permanently), this utility shall write an error
       message describing the problem and exit with a non-zero exit status.

       The uux utility cannot guarantee support for all character encodings in
       all circumstances. For example, transmission data may be restricted to
       7 bits by the underlying network, 8-bit data and filenames need not be
       portable to non-internationalized systems, and so on. Under these
       circumstances, it is recommended that only characters defined in the
       ISO/IEC 646:1991 standard International Reference Version (equivalent
       to ASCII) 7-bit range of characters be used and that only characters
       defined in the portable filename character set be used for naming
       files.

OPTIONS
       The uux utility shall conform to the Base Definitions volume of
       POSIX.1-2017, Section 12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       -j        Write the job identification string to standard output. This
                 job identification can be used by uustat to obtain the status
                 or terminate a job.

       -n        Do not notify the user if the command fails.

       -p        Make the standard input to uux the standard input to the
                 command-string.

OPERANDS
       The following operand shall be supported:

       command-string
                 A string made up of one or more arguments that are similar to
                 normal command arguments, except that the command and any
                 filenames can be prefixed by system-name!.  A null system-
                 name shall be interpreted as the local system.

STDIN
       The standard input shall not be used unless the ''--'' or -p option is
       specified; in those cases, the standard input shall be made the
       standard input of the command-string.

INPUT FILES
       Input files shall be selected according to the contents of command-
       string.

ENVIRONMENT VARIABLES
       The following environment variables shall affect the execution of uux:

       LANG      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base Definitions
                 volume of POSIX.1-2017, Section 8.2, Internationalization
                 Variables for the precedence of internationalization
                 variables used to determine the values of locale categories.)

       LC__ALL    If set to a non-empty string value, override the values of
                 all the other internationalization variables.

       LC__CTYPE  Determine the locale for the interpretation of sequences of
                 bytes of text data as characters (for example, single-byte as
                 opposed to multi-byte characters in arguments).

       LC__MESSAGES
                 Determine the locale that should be used to affect the format
                 and contents of diagnostic messages written to standard
                 error.

       NLSPATH   Determine the location of message catalogs for the processing
                 of LC__MESSAGES.

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       The standard output shall not be used unless the -j option is
       specified; in that case, the job identification string shall be written
       to standard output in the following format:


           "%s\n", <jobid>

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       Output files shall be created or written, or both, according to the
       contents of command-string.

       If -n is not used, mail files shall be modified following any command
       or file-access failures on the remote system.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       This utility is part of the UUCP Utilities option and need not be
       supported by all implementations.

       Note that, for security reasons, many installations limit the list of
       commands executable on behalf of an incoming request from uux.  Many
       sites permit little more than the receipt of mail via uux.

       Any characters special to the command interpreter should be quoted
       either by quoting the entire command-string or quoting the special
       characters as individual arguments.

       As noted in uucp, shell pattern matching notation characters appearing
       in pathnames are expanded on the appropriate local system. This is done
       under the control of local settings of LC__COLLATE and LC__CTYPE.  Thus,
       care should be taken when using bracketed filename patterns, as
       collation and typing rules may vary from one system to another. Also be
       aware that certain types of expression (that is, equivalence classes,
       character classes, and collating symbols) need not be supported on non-
       internationalized systems.

EXAMPLES
        1. The following command gets file1 from system aa and file2 from
           system bb, executes diff on the local system, and puts the results
           in file.diff in the local PUBDIR directory. (PUBDIR is the uucp
           public directory on the local system.)


               uux "!diff a!/usr/file1 b!/a4/file2 >!~/file.diff"

        2. The following command fails because uux places all files copied to
           a system in the same working directory.  Although the files xyz are
           from two different systems, their filenames are the same and
           conflict.


               uux "!diff a!/usr1/xyz b!/usr2/xyz >!~/xyz.diff"

        3. The following command succeeds (assuming diff is permitted on
           system aa) because the file local to system aa is not copied to the
           working directory, and hence does not conflict with the file from
           system cc.


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

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Chapter _2, Shell Command Language, uucp, uuencode, uustat

       The Base Definitions volume of POSIX.1-2017, Chapter _8, Environment
       Variables, Chapter 11, General Terminal Interface, Section 12.2,
       Utility Syntax Guidelines

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                               UUX(1)
