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Execute(4)
NAME
Execute - Contains instructions for running commands that require the
resources of a remote system
SYNOPSIS
/usr/spool/uucp/SystemName/X.RemoteSystemNxxxx
DESCRIPTION
The Execute (X.*) files contain instructions for running uucp commands that
require the resources of a remote system. They are created by the uux
command. The full pathname of a uux command execute file is a form of the
following:
/usr/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 4-digit
hexadecimal transfer-sequence number; for example, X.zeusN2121.
Note that 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 to 9) or letter (A to Z, a to z). Lower sequence characters
cause the file to be transmitted earlier in the connection than do higher
sequence characters. The number 0 (zero) is the highest grade, signifying
the earliest transmittal; z is the lowest grade, signifying the latest
transmittal. The default grade is N.
Standard Entries in an Execute File
An execute file consists of several lines, each with an identification
character and one or more entries:
Line Format and Description
User Line U UserName SystemName
Specifies the login name of the user issuing the uux
command and the name of the system from which the
command was issued.
Error Status Line N or Z
Indicates the error status.
The N character means that a failure message is not
sent to the user issuing the uux command if the
specified command does not execute successfully on
the remote system.
The Z character means that a failure message is sent
to the user issuing the uux command if the specified
command does not execute successfully on the remote
system.
Requester's Name R UserName
Specifies the login ID of the user requesting the
remote command execution.
Required File Line 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
pathname of the file, including the unique
transmission name assigned by the uucp program, or
simply the transmission name without any path
information.
The Required File Line can contain zero or more
filenames. The uuxqt daemon checks for the
existence of all listed files before running the
specified command.
Standard Input Line I FileName
Specifies the standard input to be used.
The standard input is either specified by a < (less
than) symbol in the command string, or is inherited
from the standard input of the uux command if that
command was issued with the - (dash) flag. If
standard input is specified, it also is listed in an
F (Required File) line. If standard input is not
specified, the uucp program uses the /dev/null
device file.
Standard Output Line O FileName SystemName
Specifies the names of the file and system that are
to receive standard output from the execution of the
command. Standard output is specified by a >
(greater than) symbol within the command string.
(The >> sequence is not valid in uux commands.) As
was the case with standard input, if standard output
is not specified, the uucp program uses the
/dev/null device file.
Command Line C CommandString
This is the command string that the user requests to
be run on the specified system. The uucp program
checks the /usr/lib/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
/usr/spool/uucp/.Xqtdir. After execution, the
standard output is sent to the requested location
EXAMPLES
1. User fong on local system zeus enters the following command:
uux - "diff /u/fong/out hera!/u/fong/out2 > ~uucp/DF"
This invokes the uux command to run a diff command on the local
system, comparing file /u/fong/out with file /u/fong/out2, 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.
This command produced the /usr/spool/uucp/hera/X.zeusN212F execute
file, which contains the following information:
U fong zeus
# return status on failure
Z
# return address for status or input return
R fong
F /usr/spool/uucp/hera/D.herale954fd out2
O ~uucp/DF zeus
C diff /u/fong/out out2
The user line identifies user fong on system zeus. The error status
line indicates that fong will receive a failure status message if the
diff command fails to execute. The requester is fong, and the file
required to execute the command is the following data file:
/usr/spool/uucp/hera/D.herale954fd out2
The output of the command is to be written to the public directory on
system zeus with the filename DF. (Remember that ~uucp is the
shorthand way of specifying the public directory.) The final line is
the command string that user fong entered with the uux command.
2. The following is another example of an execute file:
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 fong
This indicates that user uucp on system hera is sending mail to user
fong, who is also working on system hera.
FILES
/usr/lib/uucp/Permissions
Describes access permissions for remote systems
/usr/lib/uucp/Systems
Describes accessible remote systems
/usr/spool/uucp/SystemName/*
Contains uucp command, data, and execute files
/usr/spool/uucp/SystemName/C.*
Contain instructions for transfers
/usr/spool/uucp/.Xqtdir/*
Contains lists of commands that remote systems are permitted to
execute
/usr/spool/uucppublic/*
Contains files that have been transferred
RELATED INFORMATION
Daemons: uuxqt
Commands: diff(1), uux(1)
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Index for
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Alphabetical
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