Network File Copy using SSH

Network File Copy using SSH Updated February 20, 2003
Created April 23, 2001

Please note that &&, ||, and -, are documented at the bottom of this page.
PUSH:

  tar cvf - . | gzip -c -1 | ssh user@host cat ">" remotefile.gz
  ssh target_address cat <localfile ">" remotefile
  ssh target_address cat <localfile - ">" remotefile
  cat localfile | ssh target_address cat ">" remotefile
  cat localfile | ssh target_address cat - ">" remotefile
  dd if=localfile | ssh target_address dd of=remotefile
  ssh target_address cat <localfile "|" dd of=remotefile
  ssh target_address cat - <localfile "|" dd of=remotefile
  ( cd SOURCEDIR && tar cf - . ) | ssh target_address "(cd DESTDIR && tar xvpf - )"
  ( cd SOURCEDIR && tar cvf - . ) | ssh target_address "(cd DESTDIR && cat - > remotefile.tar )"
  ( cd SOURCEDIR && tar czvf - . ) | ssh target_address "(cd DESTDIR && cat - > remotefile.tgz )"
  ( cd SOURCEDIR && tar cvf - . | gzip -1 -) | ssh target_address "(cd DESTDIR && cat - > remotefile.tgz )"
  ssh target_address "( nc -l -p 9210 > remotefile & )" && cat source-file | gzip -1 - | nc target_address 9210
  cat localfile | gzip -1 - | ssh target_address cat ">" remotefile.gz

PULL:

  ssh target_address cat remotefile > localfile
  ssh target_address dd if=remotefile | dd of=localfile
  ssh target_address cat "<" remotefile >localfile
  ssh target_address cat "<" remotefile.gz | gunzip >localfile

COMPARE:

1. ##This one uses CPU cycles on the remote server to compare the files:

ssh target_address cat remotefile | diff - localfile

  cat localfile | ssh target_address diff - remotefile

###This one uses CPU cycles on the local server to compare the files:

  ssh target_address cat <localfile "|" diff - remotefile

Push: Push local file to remote server.
Pull: Pull remote file from remote server to local machine.

Of course there is always ftp, scp2, nfs, smb and other methods as well.

The above methods make a great Ghost replacement.
One can boot a system using standalone linux on a floppy, such as tomsrtbt and can then proceed to:

  backup the local hard drive to a remote server or
  download an image from the remote server and place it on the local hard drive.

RSH works just the same as SSH I'm sure, it's jut that ssh or ssh should give you better security.

Note: Compressing and then transferring data is faster than transferring uncompressed data. Use compression before sending data over the wire to achieve faster data transfer speeds.

localfile and remotefile can be files, directories, images, hard drive partitions, or hard drives.
Moving files around on local filesystem:

  ( cd SOURCEDIR && tar cf - . ) | (cd DESTDIR && tar xvpf - )

FTP VIEW:

  ftp> get file.gif "| xv -"
  ftp> get README "| more"

FTP PUSH:

  ftp> put "| tar cvf - ." myfile.tar
  ftp> put "| tar cvf - . | gzip " myfile.tar.gz

FTP PULL:

  ftp> get myfile.tar "| tar xvf -"

Pipes and Redirects:

  zcat Fig.ps.Z | gv -
  gunzip -c Fig.ps.gz | gv -
  tar xvf mydir.tar
  tar xvf - < mydir.tar
  cat mydir.tar | tar xvf -
  tar cvf mydir.tar .
  tar cvf - . > mydir.tar
  tar cf - . | (cd ~/newdir; tar xf -)
  gunzip -c foo.gz > bar
  cat foo.gz | gunzip > bar
  zcat foo.gz > bar
  gzip -c foo > bar.gz
  cat foo | gzip > bar.gz
  cat foo | gzip > bar.gz

SSH Keys
see http://www.cpqlinux.com/sshkeys.html Explanation of &&, ||, and -
&& is shorthand for „if true then do“

These can be used separately or together as needed. The following examples will attempt
to change directory to “/tmp/mydir“; you will get different results based on whether
“/tmp/mydir“ exists or not.
cd /tmp/mydir && echo was able to change directory
cd /tmp/mydir || echo was not able to change directory
cd /tmp/mydir && echo was able to change directory || echo was not able to change to directory
cd /tmp/mydir && echo success || echo failure
cd /tmp/mydir && echo success || { echo failure; exit; }

The dash “-“ is used to reference either standard input or standard output. The context in which the dash is used is what determines whether it references standard input or standard output.