uux(1p) — Linux manual page


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

PROLOG         top

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

NAME         top

       uux — remote command execution

SYNOPSIS         top

       uux [-jnp] command-string

DESCRIPTION         top

       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(1p) 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         top

       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         top

       The following operand shall be supported:

                 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         top

       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         top

       Input files shall be selected according to the contents of


       The following environment variables shall affect the execution of

       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).

                 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.



STDOUT         top

       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         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       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.



EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.



       The following sections are informative.


       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

       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         top

        1. The following command gets file1 from system a and file2 from
           system b, 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 a) because the file local to system a is not copied to
           the working directory, and hence does not conflict with the
           file from system c.

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

RATIONALE         top




SEE ALSO         top

       Chapter 2, Shell Command Language, uucp(1p), uuencode(1p),

       The Base Definitions volume of POSIX.1‐2017, Chapter 8,
       Environment Variables, Chapter 11, General Terminal Interface,
       Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       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(1P)

Pages that refer to this page: uucp(1p)