I have a backup of my site which is around 200GB(tar). I only want to extract a single file from this backup.
Any ideas on how I could go about doing this?
First you can execute this to get a list of all filenames:
tar tf archive.tar
Then using this command you can extract only the files you desire
tar xf archive.tar path/inside/archive/a.txt another/path/b.txt
Note that you may need to use z, j or another option depending on whether and what compression you've used.
Related
i used the following:
gzip -9 -c -r <some_directory> > directory.gz
how do i decompress this directory ?
I have tried
gunzip directory.gz
i am just left with a single file and not a directory structure.
As others have already mentioned, gzip is a file compression tool and not an archival tool. It cannot work with directories. When you run it with -r, it will find all files in a directory hierarchy and compress them, i.e. replacing path/to/file with path/to/file.gz. When you pass -c the gzip output is written to stdout instead of creating files. You have effectively created one big file which contains several gzip-compressed files.
Now, you could look for the gzip file header/magic number, which is 1f8b and then reconstruct your files manually.
The sensible thing to do now is to create backups (if you haven't already). Backups always help (especially with problems such as yours). Create a backup of your directory.gz file now. Then read on.
Fortunately, there's an easier way than manually reconstructing all files: using binwalk, a forensics utility which can be used to extract files from within other files. I tried it with a test file, which was created the same way as yours. Running binwalk -e file.gz will create a folder with all extracted files. It even manages to reconstruct the original file names. The hierarchy of the directories is probably lost. But at least you have your file contents and their names back. Good luck!
Remember: backups are essential.
(For completeness' sake: What you probably intended to run: tar czf directory.tar.gz directory and then tar xf directory.tar.gz)
gzip will compress 1+ files, though not meant to function like an archive utility. The posted cmd-line would yield N compressed file images concatenated to stdout, redirected to the named output file; unfortunately stuff like filenames and any dirs would not be recorded. A pair like this should work:
(create)
tar -czvf dir.tar.gz <some-dir>
(extract)
tar -xzvf dir.tar.gz
I want to download, decompress, and use a pretrained model from tensorflow-hub
After downloading I end up with a 1.tar.tar file, which I probably need to extract / decompress in order to be able to use it.
I can't wrap my head around how, I am working in a Linux terminal.
If your tar file is compressed using tar compression, use this command to decompress it. Make sure to be in the directory of the tar.tar file, it will decompress everything into the directory you are currently in.
$ tar xvzf 1.tar.tar
Where,
x: This option tells tar to extract the files.
v: The “v” stands for “verbose.” This option will list all of the files one by one in the archive.
z: The z option is very important and tells the tar command to uncompress the file.
f: This options tells tar that you are going to give it a file name to work with.
Nice to know:
A tarball is a group or archive of files that are bundled together using the tar command and have the .tar file extension.
Hi I work with fedora 17 and I want to create zip file
There are four files in my directory /tmp/manager/
sos.prj
sos.shp
sos.shx
sbb.shh
I want to create zip file from sos.prj,sos.shp,sos.shx files
I want to use grep. In other words, I want to create zip file from grep's result
Can anybody help me?
zip myArchiveName *.{prj,shp,shx}
This will zip all files with your extensions listed into a zip file named myArchiveName.zip
People normally use tar and some archiver, examples:
tar czf manager.tar.gz /tmp/manager/
tar cjf manager.tar.bz2 /tmp/manager/
tar cJf manager.tar.xz /tmp/manager/
.xz format often yields the highest compression ratio and this is the compression format used for .rpm in Fedora.
Perhaps the OP was thinking of using grep to find all the sos.* files but as #Impossibear says it's easier to just use a wildcard. If you want to focus on sos files, you could use zip myArchive sos.*
so I did this
tar cvzf test.zip FP
with the intention of creating a zip of the directory FP
however, it instead lists the directories inside the zip
FP/
FP/php/
FP/php/pdf/
FP/php/docs/
FP/aspnet/
FP/aspnet/pdf/
FP/aspnet/docs/
how do I go about tarring the directory?
Your command is good indeed.
Listing appear when specifying v option (in 'cvzf')
You can check what a gzipped tar file contain by running
$ tar tzvf test.zip
By the way you should avoid to put .zip extension on a "gzipped" tar file. If you really want to make a zip, use 'zip' package instead.
I think it DID create it. The list is just the command being verbose (-v).
I want to update an existing tar file with newer files.
At GNU, I read:
4.2.3 Updating an Archive
In the previous section, you learned how to use ‘--append’ to add a
file to an existing archive. A related operation is ‘--update’ (‘-u’).
The ‘--update’ operation updates a tar archive by comparing the date
of the specified archive members against the date of the file with the
same name. If the file has been modified more recently than the
archive member, then the newer version of the file is added to the
archive (as with ‘--append’).
However,
When I run my tar update command, the files are appended even though their modification dates are exactly the same. I want to ONLY append where modification dates of files to be tarred are newer than those already in the tar...
tar -uf ./tarfile.tar /localdirectory/ >/dev/null 2>&1
Currently, every time I update, the tar doubles in size...
The update you describe implies that the file within the archive is replaced. If the new copy is smaller than what's in the archive, it could be directly rewritten. If the new copy however is larger, tar would have to zero the existing archive entry and append. Such updates would leave runs of '\0's or other unused bytes, so any normal computer user would want that such sections are removed, which would be done by "moving up" bytes comprising the archive contents towards the start of the file (think C's memmove).
Such an in-place move operation however, which would involve seek-read-seek-write cycles, is costly, especially when you look at it in the context of tapes — which tar was designed for originally —, i.e. devices with a seek performance that is not comparable to harddisks. You'd wear out the tape rather quickly with such move ops. Oh and of course, WORM devices don't support this move op either.
If you do not want to use the "-P" switch tar -u... works correctly if the current directory is the parent directory of the one we are going to update, and the path to this directory in the tar command will not be an absolute path.
For exmple:
We want to update catalog /home/blabla/Dir. We do it like that:
cd /home/blabla
tar -u -f tarfile.tar Dir
In general, the update must be made from the same place as the creation, so that the paths agree.
It is also possible:
cd /home/blabla/Dir
tar-u -f /path/to/tarfile.tar .
You may simply create (instead of update) the archive each time:
tar -cvpf tarfile.tar *
This will solve the problem of your archive doubling in size each time. But of course, it is generating the whole archive every time.
By default tar strips the leading / from member names, but it does this after deciding what needs to be updated.
Therefore if you are archiving an absolute path, you either need to cd / and use relative paths, or add the -P/--absolute-names option.
cd /
tar -uf "$OLDPWD/tarfile.tar" localdirectory/ >/dev/null 2>&1
tar -cPf tarfile.tar /localdirectory/ >/dev/null 2>&1
tar -uPf tarfile.tar /localdirectory/ >/dev/null 2>&1
However, the updated items will still be appended. A tar (tape archive) file cannot be modified excpet by appending.
Warning! When speaking about "dates" it means any date, and that includes the access time.
Should your files have been accessed in any such way (a simple ls -l is enough) then tar is right to do what it does!
You need to find another way to do what you want. Probably use a sentinel file and see if its modification date is less than the files you wish to append.