Commands tagged gzip

If you have servers on Wide Area Network (WAN), you may experience very long transfer rates due to limited bandwidth and latency.

To speed up you transfers you need to compress the data so you will have less to transfer.

So the solution is to use a compression tools like gzip or bzip or compress before and after the data transfer.

Using ssh "-C" option is not compatible with every ssh version (ssh2 for instance).

This improves on #9892 by compressing the directory on the remote machine so that the amount of data transferred over the network is much smaller. The command uses ssh(1) to get to a remote host, uses tar(1) to archive and compress a remote directory, prints the result to STDOUT, which is written to a local file. In other words, we are archiving and compressing a remote directory to our local box.

The command uses ssh(1) to get to a remote host, uses tar(1) to archive a remote directory, prints the result to STDOUT, which is piped to gzip(1) to compress to a local file. In other words, we are archiving and compressing a remote directory to our local box.

the -a flag causes tar to automatically pick the right compressor to filter the archive through, based on the file extension. e.g.

"tar -xaf archive.tar.xz" is equivalent to "tar -xJf archive.tar.xz"

"tar -xaf archive.tar.gz" is equivalent to "tar -xzf archive.tar.gz"

No need to remember -z is gzip, -j is bzip2, -Z is .Z, -J is xz, and so on :)

This version compresses the data for transport.

Get gzip compressed web page using wget.

Caution: The command will fail in case website doesn't return gzip encoded content, though most of thw websites have gzip support now a days.

This is freaking sweet!!! Here is the full alias, (I didn't want to cause display problems on commandlinefu.com's homepage):

Creates a .tgz archive of whatever directory it is run from, in the background, detached from current shell so if you logout it will still complete. Also, you can run this as many times as you want, if the archive .tgz already exists, it just moves it to a numbered backup '--backup=numbered'. The coolest part of this is the transformation performed by tar and sed so that the archive file names are automatically created, and when you extract the archive file it is completely safe thanks to the transform command.

If you archive lets say /home/tombdigger/new-stuff-to-backup/ it will create the archive /home/#home#tombdigger#new-stuff-to-backup#-2010-11-18.tgz Then when you extract it, like tar -xvzf #home#tombdigger#new-stuff-to-backup#-2010-11-18.tgz instead of overwriting an existing /home/tombdigger/new-stuff-to-backup/ directory, it will extract to /home/tombdigger/new-stuff-to-backup.2010-11-18/

Basically, the tar archive filename is the PWD with all '/' replaced with '#', and the date is appended to the name so that multiple archives are easily managed. This example saves all archives to your $HOME/archive-name.tgz, but I have a $BKDIR variable with my backup location for each shell user, so I just replaced HOME with BKDIR in the alias.

So when I ran this in /opt/askapache/SOURCE/lockfile-progs-0.1.11/ the archive was created at /askapache-bk/#opt#askapache#SOURCE#lockfile-progs-0.1.11#-2010-11-18.tgz

Upon completion, uses the universal logger tool to output its completion to syslog and stderr (printed to your terminal), just remove that part if you don't want it, or just remove the '-s ' option from logger to keep the logs only in syslog and not on your terminal.

Here's how my syslog server recorded this..

2010-11-18T00:44:13-05:00 gravedigger.askapache.com (127.0.0.5) [user] [notice] (logger:) Tarred /opt/askapache/SOURCE/lockfile-progs-0.1.11 to /askapache-bk/tarred/#opt#SOURCE#lockfile-progs-0.1.11#-2010-11-18.tgz in 4 seconds

Caveats

Really this is very robust and foolproof, the only issues I ever have with it (I've been using this for years on my web servers) is if you run it in a directory and then a file changes in that directory, you get a warning message and your archive might have a problem for the changed file. This happens when running this in a logs directory, a temp dir, etc.. That's the only issue I've ever had, really nothing more than a heads up.

Advanced:

This is a simple alias, and very useful as it works on basically every linux box with semi-current tar and GNU coreutils, bash, and sed.. But if you want to customize it or pass parameters (like a dir to backup instead of pwd), check out this function I use.. this is what I created the alias from BTW, replacing my aa_status function with logger, and adding $SECONDS runtime instead of using tar's --totals

{

local GZIP='--fast' PWD=${1:-`pwd`} F=$(date +${BKDIR}/%m-%d-%g-%H%M-`sed -u 's/[\/\ ]/#/g'

[[ ! -r "$PWD" ]] && echo "Bad permissions for $PWD" 1>&2 && return 2;

( ( tar --totals --ignore-failed-read --transform "s@^${PWD%/*}@`date +${PWD%/*}.%m-%d-%g`@S" -czPf $F $PWD && aa_status "Completed Tarp of $PWD to $F" ) & )

}

#From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

The gzexe utility allows you to compress executables in place and have them automatically uncompress and execute when you run them. FYI: You can compress any executable sha-bang scripts as well (py, pl, sh, tcl, etc.).

Opens a snapshot of a live UFS2 filesystem, runs dump to generate a full filesystem backup which is run through gzip. The filesystem must support snapshots and have a .snap directory in the filesystem root.

To restore the backup, one can do

Should do exactly the same - compress every file in the current directory. You can even use it recursively:

This way you keep the file compressed saving disk space.

Other way less optimal using named pipes:

mysql -uroot -p'passwd' database <

It grabs all the database names granted for the $MYSQLUSER and gzip them to a remote host via SSH.

What happens here is we tell tar to create "-c" an archive of all files in current dir "." (recursively) and output the data to stdout "-f -". Next we specify the size "-s" to pv of all files in current dir. The "du -sb . | awk ?{print $1}?" returns number of bytes in current dir, and it gets fed as "-s" parameter to pv. Next we gzip the whole content and output the result to out.tgz file. This way "pv" knows how much data is still left to be processed and shows us that it will take yet another 4 mins 49 secs to finish.

Credit: Peteris Krumins http://www.catonmat.net/blog/unix-utilities-pipe-viewer/

Use `zless` to read the content of your *rss.gz file:

Create a single tar.gz archive

I know it's a very basic one, but it's one I keep forgetting.

Where foodir is the directory you want to zip up.