Ask MetaFilter questions tagged with tar

Why did tar and nc not play nice?

flabdablet — Sat, 26 Sep 2009 17:54:13 -0800

Can anybody immediately see why nc and tar didn't work together the way I expected they would? I wanted to copy an Ubuntu installation from a laptop with one filesystem to a desktop box with two. So I booted an Ubuntu live CD on each and opened terminals; then on the laptop did



sudo su -

mount /dev/sda2 /mnt

cd /mnt

tar c . | nc -l -p 10000

and on the desktop box did



sudo su -

mkfs -t ext3 -L root /dev/sda3

mkfs -t ext3 -L home /dev/sda4

mount /dev/sda3 /mnt

mkdir /mnt/home

mount /dev/sda4 /mnt/home

cd /mnt

nc 192.168.1.3 10000 -q5 | tar xv --numeric-owner

As expected, a huge list of filenames scrolled by on the desktop box as tar extracted the files. When that all stopped, I hit ctrl-D on the desktop end to close nc's standard input; five seconds later the shell prompt returned on the laptop as well. So everything seemed to be working as expected.

After making the necessary corrections to /mnt/boot/grub/menu.lst, /mnt/etc/fstab, /mnt/etc/hosts and /mnt/etc/hostname on the desktop box, I umounted everything and rebooted it, but assorted things were badly amiss. Turns out that a random assortment of vital files had been created with zero length and zero permissions instead of being properly copied.

I have since got the machine-to-machine copy done by mounting the laptop's hard drive in a USB enclosure, plugging it into the desktop box and using cp -av so I'm not looking for ways to get the primary job done any more.

What I would like to know: before I spend more time trying to work out why the tar | nc <--> nc | tar method failed, can anybody see some documented reason why it was doomed to do so?

Efficiently retrieving a file from an archive

Blazecock Pileon — Thu, 27 Aug 2009 16:25:43 -0800

Is there a smarter tar or cpio out there, or a smarter way to archive, to efficiently retrieve a file stored in the archive? I am using tar to archive a group of very large (multi-GB) bz2 files.

If I use tar -tf file.tar to list the files within the archive, this takes a very long time to complete (~10-15 minutes).

Likewise, cpio -t < file.cpio takes just as long to complete, plus or minus a few seconds.

Accordingly, retrieving a file from an archive (via tar -xf file.tar myFileOfInterest for example) is as slow.

Is there an archival method out there that keeps a readily available "catalog" with the archive, so that an individual file within the archive can be retrieved quickly?

For example, some kind of catalog that stores a pointer to a particular byte in the archive, as well as the size of the file to be retrieved (as well as any other filesystem-specific particulars).

Is there a tool (or argument to tar or cpio) that allows efficient retrieval of a file within the archive?

reveal the mystic truth!

garethspor — Tue, 31 Mar 2009 22:33:55 -0800

What is the explanation for spirals of crack-sealing tar I see on the roads periodically? Examples here and here.

I photographed these in Golden Gate Park, San Francisco.

OSX: Future as a programmer dashed by failure to interpret Terminal error

metajc — Wed, 20 Aug 2008 18:49:53 -0800

Multiple sources credit this Hivelogic post as the definitive guide to getting MySQL up and running on a Mac OS X. But I can't get past the first few steps. I am not a programmer. But I wish I was; they earn more than me and have the best office in the building. I know HTML and CSS and basic PHP. I have been trying out a bunch of Ruby, Python, Django, and PHP tutorials lately but they're all kind of useless because they're not directly applicable to a hosted, "live site" environment that I'm used to ... So, I'm trying to install MySQL on my Intel Macs running 10.5.4 (powerbook and imac) to have a local testing environment but BANG I'm an idiot and I cannot get through this apparently simple tutorial. Of course, the comments are closed and my Googling yields no answer. I was about to give up when I remembered my good friends over here.

Here's what happens, I try to download and build MySQL as instructed:

curl -O http://mysql.he.net/Downloads/MySQL-5.0/mysql-5.0.45.tar.gz
tar xzvf mysql-5.0.45.tar.gz

But I get the following error:

gzip: stdin: not in gzip format
tar: Child returned status 1
tar: Error exit delayed from previous errors

I've tried downloading newer versions of MySQL but I just don't know what I'm doing.

working with tar archives...

timebomb — Wed, 13 Aug 2008 22:10:43 -0800

How can get the sum of the files sizes of all php and css files within specific folders of a tar archive? Ultimately, I want to create a graph showing how code grew over the duration of a project. To do that, I would like to build a script that sums the sizes specific files of specific types within specific directories of the archive file.

I have a folder containing a couple hundred backup files of a web development server. The backup files were archived using the "tar czf" command line.

In each archive file, I want to search within the following directories for php and css files:
var/www/dev/
var/www/dev/includes
var/www/dev/css
Subdirectories of these directories should not be searched.

Can you guys get me on my way?

So far I'm stuck trying to list files I need in the tar file. I have:
tar -ztvf archive_name.tgz var/www/dev/
which is listing all subdirectories and all file types.

The OS is Ubuntu 8.04 Server Edition

Thanks in advance!

How to exorcise cigarette smells and tar from an iMac?

mattybonez — Mon, 28 Apr 2008 10:32:26 -0800

How can I clean away cigarette odor and tar buildup from a G3 iMac? I loaned an old iMac to a friend who needed a computer after his house was burgled. The “week or two” loan turned into many months, and I finally got the computer back last night.

When I saw the condition of my previously minty Mac, I was very sad. The keyboard, mouse, and computer are all showing signs of living with chain smokers. There is some tar discoloration in the clear plastic bits, and there is also a very distinct smell. It's strong enough that I can't bring the computer into my house.

I'm planning on taking apart the components and cleaning them up, but wanted to know if anyone had any additional tips or suggestions before I get started. Any idea on cleaning agents that I can use that won't craze the plastic?

Thanks in advance.

How do I open a ".tar.tgz" file?

exolstice — Sat, 29 Mar 2008 05:31:19 -0800

How do I open a ".tar.tgz" file? That's all one long extension. I have a friend who's hosting package expired on www.canaca.com. So I immediately logged-in to backup his information. The problem is the backup function gives me a huge file with a .tar.tgz extension. Now I would like to take the contents of that file and upload to my own hosting service. I tried uncompressing with WinZip, WinRar, WinAce, ZipGenius, StuffIt, Gzip, GUnzip, and more! None of these programs recognize the file as a valid archive. I uploaded the file to my hosting service, and attempted to extract it from there. Same result. I also redownloaded the backup, thinking the original file may have been corrupted, but I got the exact same file down to the byte.

They seem to have disconnected the ftp access, so I can no longer access the files that way. The backup function is my only option.

So am I stuck with a proprietary file which can only be uncompressed on www.canaca.com or is there another way to crack this nut?

Thanks!

tar on my car :(

(lambda (x) x) — Wed, 18 Oct 2006 15:40:39 -0800

I drove through a work area today and my car is covered in tar. What can I do? On my way home from work I passed through a work area on a rural state road where they were filling cracks on the road with a tar/asphalt substance. It was the typical situation where they have two guys with stop/slow signs at each end of the temporarily one-lane road. They directed me through, and a few minutes later I noticed that my steering wheel was unusually wobbly. When I got home, I got out and saw that my tires were covered in tar/asphalt. It also splashed around the wheel wells. This stuff is incredibly sticky, and it seems to be hardening. I can't get it off myself. Will I need new tires, or is it possible that a tire shop will be able to clean this off? What about the body, should I even try to get it off myself?

Also, would it be worth trying to get the state DOT to foot the bill? Ugh.

Quicker WordPress upgrades?

pzarquon — Tue, 14 Mar 2006 20:02:21 -0800

I'm trying to keep up with WordPress upgrades (2.0.2 just came out yesterday, and I was only halfway through upgrading 30 installs to 2.0.1!), but I swear there must be an easier way than the way I'm doing it. I run multiple installs of WordPress. I run them in renamed directories (domain.com/bob), rather than keeping the default (domain.com/wordpress). When a new version comes out, here's what I do at the command line:

1. Rename the directory ('bob' to 'bob.old').

2. Unpack the new version (tar -xvzf wordpress-x-x-x.tar.gz), which automatically puts itself in a directory called 'wordpress'.

3. Rename 'wordpress' to 'bob'.

4. Copy the wp-config.php, .htaccess, plugins, and assorted theme files from 'bob.old' to 'bob.'

Step four is a pain, and I frequently miss things I should have copied over, so I keep looking at step 2 and thinking there must be an easier way. The documentation says to just install the new files over the old files (and the installer uses filenames like wp-config-sample.php to make sure it doesn't overwrite your actual config file), but apart from FTP, how do I do that with the tar command? In other words, how can I tell tar to unpack the contents of the file into the pre-existing 'bob' rather than into a 'wordpress' directory?

I know there are other WordPress gurus here, and I'm hoping I'm just missing something so blatantly obvious it'll hurt to read the answer.

Family Guy in Japan?

furiousxgeorge — Tue, 08 Mar 2005 02:43:51 -0800

Is the show "Family Guy" on the air in Japan at all? Do the Japanese like it? Is any American animation popular in Japan? I ask because I am an American and a big fan of Japanese animation...is the fascination cross-cultural?