Purpose
Contains file transfer
directions for the uucico daemon.
Description
Command (C.*) files contain the directions that the Basic Networking Utilities
(BNU) uucico daemon follows when transferring files. The
full path name of a command file is a form of the following:
/var/spool/uucp/SystemName/C.SystemNameNxxxx
The SystemName variable indicates the name of the
remote system. The N character represents the grade of the
work. The xxxx notation is the four-digit hexadecimal transfer-sequence
number; for example, C.merlinC3119.
The grade of the
work specifies when the file is to be transmitted during a particular
connection. The grade notation characteristics are:
- 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. Sequence is
established using ASCII order, beginning with 0 and ending with z.
- The number 0 is the highest grade (that is, the lowest character
in the sequence), signifying the earliest transmittal; z is the lowest
grade, specifying the latest transmittal.
- The default grade is N.
A command file consists of a single line that includes the
following kinds of information in the following order:
- An S (send) or R (receive) notation.
Note: A send command file
is created by the
uucp or
uuto commands; a receive command file is created by
the
uux command.
- The full path name of the source file being transferred. A receive command file does
not include this entry.
- The full path name of the destination file, or a path name preceded
by ~user, where user is a login name on the specified
system. Here, the ~ (tilde) is shorthand for the name of the user's
home directory.
- The sender's login name.
- A list of the options, if any, included with the uucp, uuto, or uux command.
- The name of the data file associated with the command file in
the spooling directory. This field must contain an entry. If one of
the data-transfer commands (such as the uucp command with the
default -c flag) does not create a data file, the BNU program
instead creates a placeholder with the name D.0 for send files
or the name dummy for receive files.
- The source file permissions code, specified as a three-digit octal
number (for example, 777).
- The login name of the user on the remote system who is to be notified
when the transfer is complete.
Examples
The following are
two examples of using the command (C.*) files.
Two Send Command Files
- The send command file /var/spool/uucp/venus/C.heraN1133, created with the uucp command, contains the following fields:
S /home/amy/f1 /var/spool/uucppublic/f2 amy -dC D.herale73655 777 lgh
where:
- S denotes that the uucp command is sending the
file.
- The full path name of the source file is /home/amy/f1.
- The full path name of the destination is /var/spool/uucppublic/f2, where /var/spool/uucppublic is the name of the BNU public
spooling directory on the remote computer and f2 is the new
name of the file.
Note: The destination name may be abbreviated as ~/f2. Here, the ~ (tilde) is a shorthand way of designating
the public directory.
- The person sending the file is amy.
- The sender entered the uucp command with the -C flag,
specifying that the uucp command program should transfer the
file to the local spooling directory and create a data file for it.
(The -d flag, which specifies that the command should create
any intermediate directories needed to copy the source file to the
destination, is a default.)
- The name of the data (D.*) file is D.herale73655, which the uucp command assigns.
- The octal permissions code is 777.
- The lgh login name of the user on system hera, who is to be notified of the file arrival.
- The /var/spool/uucp/hera/C.zeusN3130 send command file,
produced by the uuto command, is as follows:
S /home/amy/out ~/receive/msg/zeus amy -dcn D.0 777 msg
The
S denotes that the
/home/amy/out source
file was sent to the
receive/msg subdirectory in the public
spooling directory on system
zeus by user
amy.
Note: The uuto command creates the receive/msg directory
if it does not already exist.
The uuto command
used the default flags -d (create directories), -c (transfer
directly, no spooling directory or data file), and -n (notify
recipient). The D.0 notation is a placeholder, 777 is the permissions code, and msg is the recipient.
Receive Command File
The
format of a receive command file is somewhat different from that of
a send command file. When files required to run a specified command
on a remote system are not present on that system, the uux command
creates a receive command file.
For example, the following
command:
uux - "diff /home/amy/out hera!/home/amy/out2 > ~/DF"
produces the
/var/spool/uucp/zeus/C.heraR1e94 receive
command file.
Note: The command in this example invokes the
uux command to run a
diff command on the local system, comparing file
/home/amy/out with file
/home/amy/out2, which is stored
on the remote system
hera. The output of the comparison is
placed in the
DF file in the public directory on the local
system.
The actual receive command file looks like this:
R /home/amy/out2 D.hera1e954fd amy - dummy 0666 amy
The R denotes a receive file. The uucico daemon,
called by the uux command, gets the /home/amy/out2 file from system hera and places it in a data file called D.hera1e954fd for the transfer. Once the files are transferred,
the uuxqt daemon executes the command on the specified
system.
User amy issued the uux command with
the - (minus sign) flag, which makes the standard input to the uux command the standard input to the actual command string.
No data file was created in the local spooling directory, so the BNU
program uses dummy as a placeholder. The permissions code
is 666 (the BNU program prefixes the three-digit octal code
with a 0), and user amy is to be notified when the
command has finished executing.