Copying ARC/INFO coverages between machines
Software: ARC/INFO, all versions
Platform: ALL
Question:
What is the best way to tansfer ARC/INFO coverages?
Cause:
Not applicable
Answer:
There are several methods for copying ARC/INFO coverages between two computers.
These methods require these choices:
- Send ARC/INFO export (.e00) files, or a whole workspace
- Whether to, and how to, consolidate files together for delivery
- Whether to, and how to, compress the files
These choices are determined by :
- The number and arrangement of coverages
- The computers' operating systems (MS-DOS or UNIX)
- The transfer method (floppy disk, tape, or over a network)
Choosing between EXPORT files, or workspace
===========================================
ARC/INFO EXPORT (.e00) format is the safest, most reliable way to copy ARC/INFO coverages. An EXPORT format file is created by the ARC/INFO EXPORT command, which puts all the information in a coverage into one file. This includes any INFO tables that are associated with the coverage. Actually, ARC/INFO just looks for any INFO tables (in the same workspace as the coverage) that begin with the coverage's name. For example, qbec_bc.pat will be exported along with the coverage qbec_bc.
If the coverage is in single precision its export file can usually be imported into PC ARC/INFO, or ArcView2.
The export file has a '.e00' extension, and can be copied with UNIX cp, rcp, ftp, etc.
To export a coverage, use the ARC/INFO EXPORT command:
Arc: EXPORT COVER coverage_name filename FULL
The ARC/INFO IMPORT command will re-create a coverage from the .e00 export file. For example, to import an export coverage into the $ARCLIB directory:
Arc: IMPORT COVER filename $ARCLIB/coverage_name
(You don't need the .e00 on the filename)
A WORKSPACE is the easiest way to transfer a collection of coverages that belong together between computers with the same operating system (ie UNIX or MS-DOS).
A workspace is the ARC/INFO term for a disk directory which contains the files that make up a collection of coverages. There is one subdirectory for each coverage, plus an extra 'info' directory. To copy ALL the coverages in a workspace, just transfer the whole directory structure.
Consolidate for delivery
========================
If you are transferring a UNIX workspace over the network, you should first use the UNIX 'tar' command to combine all the files in the workspace into one '.tar' file. This preserves the directory structure.
% cd workspace
% cd ..
% tar cvf workspace.tar workspace
To verify the workspace.tar file was created properly, use the 'tv' option to list the files in it:
% tar tvf workspace.tar
Compress the files
==================
Compression reduces the physical size of a file by storing its data more efficiently. It is recommended to use a compression utility program before storing or transferring files, and then uncompress them with a matching program before using. For instance, files compressed with PKZIP will be uncompressed with PKUNZIP.
If you are transferring data on floppies using PKZIP, it has compression built in. If you are transferring data on tar tapes, compression is usually unnecessary, because the tapes hold a lot of data.
Before transferring export or .tar files between UNIX computers over the network, you should reduce the size of the files with the UNIX compress command. Although the UNIX compress may not use the most efficient compression techniques, it is available on all UNIX computers.
To compress an export file:
% compress filename.e00
This replaces filename.e00 with filename.e00.Z
To compress a .tar file:
% compress filename.tar
This replaces filename.tar with filename.tar.Z
To restore a compressed file to its former glory, use <b>uncompress:
% uncompress filename.e00.Z
Copying files on floppies
=========================
To copy files between computers running MS-DOS, the simplest method may be to use 1.44 MB floppy diskettes. The PKZIP utility is a simple way to copy a set of export files or workspaces onto a set of floppy diskettes. It compresses the data as it writes it.
To copy a set of export files, put them in a directory and issue this DOS command:
C:> PKZIP -&w A:\DATA.ZIP *.e00
The '-&w' tells PKZIP to 'span disks' if the data won't fit on one disk.
To copy a complete workspace, go to the workspace and issue this DOS command:
C:> CD workspace
C:> CD ..
C:> PKZIP -r -&w A:\DATA.ZIP workspace
The '-r' tells PKZIP to preserve the directory structure of the workspace.
To make sure that the data was copied on properly, issue this DOS command:
C:> PKUNZIP -t A:\DATA.ZIP
PKUNZIP will check the data on disk to make sure it is not corrupted.
Copying UNIX files on tape
==========================
To copy UNIX files on tape, use the UNIX 'tar' command. It will copy a group of files or directory trees directly onto a tape with one command.
Put a tape in the tape drive, and use the UNIX 'mt' command to make sure that the tape drive is hooked up properly for you:
% mt rewind
If this command issues an error, contact your system administrator.
Go to the directory containing the data and use the tar command with the 'c' option to copy the files directly onto the tape. To copy a set of export files from a directory:
% cd directory
% tar cv *.e00
To copy a complete workspace:
% cd workspace
% cd ..
% tar cv workspace
To make sure they copied properly, use the 'tv' option to list the files on the tape:
% tar tv
Copying MS-DOS files on tape
============================
Tape drives can be hooked up to the parallel port on a PC for backup and data transport purposes. These come with their own backup/restore utilities, and so you should refer to your tape drive's manual for using such utilities.
Before using a tape drive to transfer data, it is important to make sure the recipient's
device and software are compatible.
Copying files with ftp
======================
UNIX provides 'anonymous ftp' as a standard mechanism for transferring data over the
Internet. To fetch files from another computer using ftp, follow these steps:
From UNIX (or DOS), enter the ftp command:
% ftp nodename
(for example ftp ssbux2.env.gov.bc.ca)
At the username: prompt, enter anonymous. At the password prompt, enter your UNIX username and hostname. For example : gsmith@gizmo.bus.gov.bc.ca. You are now logged on to nodename, with a very restricted set of privileges available to 'anonymous ftp' users. Use the cd
command to move to the right directory.
ftp> cd directory
Use the ls command to make sure the files are there.
ftp> ls
If you are going to fetch one or two files, use the get command to transfer the files.
ftp> get filename1
ftp> get filename2
If you are going to fetch several files, turn prompting off, and use the mget command to transfer the files.
ftp> prompt no
ftp> mget *.e00.Z
quit ftp
ftp> quit
If you want to send files to another computer, rather than fetch them, use the put or mput command, in place of get above.
Notes:
The above data was obtained from:
http://www.env.gov.bc.ca/gis/arccopy.html
Related Documents:
2129 - Guidelines for transferring e00 files from one platform to another
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