Command - Contains file transfer directions for the uucico daemon
Command (C.*) files contain the directions that the uucp uucico daemon fol-
lows when transferring files. The full pathname of a command file is a
form of the following:
/C.SystemName indicates the name of the remote system. N represents the
grade of the work, and xxxx is the 4-digit hexadecimal transfer-sequence
number; for example, C.merlinCE01F.
The grade of the work specifies when the file is to be transmitted during a
particular connection. The grade notation has the following characteris-
+ It 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.
A command file consists of a single line that includes the following kinds
of information in the following order:
1. An S (send) or R (receive) notation. Note that a send command file is
created by the uucp or uuto commands; a receive command file is
created by the uux command.
2. The full pathname of the source file being transferred. A receive
command file does not include this entry.
3. The full pathname of the destination file, or a pathname preceded by
~user (tilde user), where user is a login name on the specified sys-
tem. Here, the tilde is shorthand for the name of the user's home
4. The sender's login name.
5. A list of the options, if any, included with the uucp, uuto, or uux
6. 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 uucp program instead creates a
placeholder with the name D.0 for send files, or dummy for receive
7. The source file permissions code, specified as a 3-digit octal number
(for example, 777).
8. The login name of the user on the remote system who is to be notified
when the transfer is complete.
Examples of send command and receive command files follow.
Examples of Two Send Command Files
1. The send command file /usr/spool/uucp/venus/C.heraN1133, created with
the uucp command, contains the following fields:
S /u/betp/f1 /usr/spool/uucppublic/f2 betp .nL
-dC D.herale3655 777 jmp
The fields are as follows:
+ The S keyword denotes that the uucp command is sending the file.
+ The full pathname of the source file is /u/betp/f1.
+ The full pathname of the destination is /usr/spool/uucppublic/f2,
where /usr/spool/uucppublic is the name of the uucp public spool-
ing directory on the remote computer and f2 is the new name of
Note that when the user's login ID is uucp, the destination name
may be abbreviated as ~ uucp/f2. Here, the ~ (tilde) is a short-
hand way of designating the public directory.
+ The person sending the file is betp.
+ 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 inter-
mediate directories needed to copy the source file to the desti-
nation, is the default.)
+ The name of the Data (D.*) file is D.herale3655, which the uucp
+ The octal permissions code is 777.
+ On system hera, jmp is the login name of the user who is to be
notified of the file arrival.
2. The /usr/spool/uucp/hera/C.zeusN3130 send command file, produced by
the uuto command, is as follows:
S /u/betp/out ~/receive/msg/zeus betp .nL
-dcn D.0 777[4~ msg
+ The S denotes that the /u/betp/out source file was sent to the
receive/msg subdirectory in the public spooling directory on sys-
tem zeus by user betp.
+ The uuto command used the default flags -d (create directories),
-c (transfer directly, no spooling directory or data file), and
-n (notify recipient).
Note that the uuto command creates the receive/msg directory if
it does not already exist.
+ The D.0 notation is a placeholder, 777 is the permissions code,
and msg is the recipient.
Example of a 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 produces the
/usr/spool/uucp/zeus/C.heraR1e94 receive command file:
uux - "diff /u/betp/out hera!/u/betp/out2 >> ~uucp/DF"
Note that the command in this example invokes the uux command to run a
diff command on the local system, comparing file /u/betp/out with file
/u/betp/out2, which is stored on remote system hera. The output of
the comparison is placed in file DF in the public directory on the
The actual receive command file looks like this:
R /u/betp/out2 D.hera1e954fd betp - dummy 0666 betp
The R denotes a receive file. The uucico daemon, called by the uux
command, gets the /u/betp/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 betp issued the uux command with the - (dash) 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 uucp program uses dummy as a placeholder.
The permissions code is 666 (the uucp program prefixes the 3-digit
octal code with a 0 [zero]), and user betp is to be notified when the
command finishes executing.
Describes access permissions for remote systems
Describes accessible remote systems
Contains uucp command, data, and execute files
Contain data to be transferred
Contains transferred files
Commands: uucp(1), uupick(1), uuto(1), uux(1), uuxqt(1), uudemon(4),
cron(8), uucico(8), uusched(8)