The compression tag has no wiki summary.
-2
votes
1answer
38 views
file type determine [closed]
As part of the product, there were several scripts which was provided.
In one of the scripts, I've found the following line which seems not to work properly
find . -name *.old -type f -mtime +7 | ...
7
votes
3answers
183 views
Universal extractors
With an increasing number of archive/compression file formats, is there a single free/open-source command line tool to rule them all? Perhaps something with a consistent / unified set of flags? (note ...
1
vote
1answer
46 views
Difference between --xz and --lzma in GNU tar?
As far as I can tell, XZ is a container that uses the LZMA2 algorithm (i.e. extended LZMA); but e.g.
$ xz foo/
complains about foo/ being a directory. So presumably the correct way to preserve ...
3
votes
8answers
1k views
Triple compression and I only save 1% in space?
I've been trying to save space on my linux server, and I had a folder containting, in subfolders, 22GB of images.
So I decided to compress them.
First I used tar:
tar -zcf folder.tar folder
Then ...
2
votes
1answer
87 views
Will using a compressed filesystem over an encrypted volume improve performance?
Encryption/decryption is often the main bottleneck when accessing an encrypted volume. Would using a filesystem with a fast transparent compression (such as BTRFS + LZO) help? The idea is that there ...
0
votes
2answers
69 views
Can tar archiver zerofill a file?
I have received a tar archive from a co-worker and after decompresing I found that some text files are corrupted. More precisely they are filled with zeros. They have correct size but all bytes are ...
-2
votes
3answers
123 views
Determine whether a particular file is compressed
How to know in Linux whether a particular file is compressed or not using a command?
-1
votes
2answers
121 views
Can I compress a compressed file more?
I have access to a server via SSH, I download files from it over SFTP or HTTP. I want to pull down a 4.4GB .mkv file but I have limited bandwidth.
I have used zip, gzip and p7zip, but the file is ...
5
votes
1answer
154 views
On the Fly Compression for a Directory
I have a directory that is always going to be storing text files that are rarely (think weekly) used. Naturally this is a great place to use compression. However, rather than having to use tar ever ...
2
votes
2answers
110 views
Different count for compressed file listing vs directory listing
I was taking a backup of a folder, where I used the following command :
sudo tar -zcvf www.tar.gz /var/www/
It successfully compressed, just for verifying the number of files in the compressed ...
0
votes
1answer
181 views
Uncompress txt.gz files
Trying to uncompress txt.gz files on Linux. gzip, gunzip, unzip are not recognizing the file format. The archive is guaranteed to be not corrupted.
1
vote
0answers
37 views
Is it possible to get specific information about how a file is compressed?
File compression works on the basic idea of assigning commonly recurring chains of strings to a common index of a table where the full string is stored.
For example:
Input file: foo bar bash baz foo ...
0
votes
0answers
28 views
How to decompress content of various archive types with one command [duplicate]
Possible Duplicate:
Is there any program to provide a consistent interface across multiple archive types?
I have to handle files that come as uncompressed text files or in various archive ...
2
votes
1answer
49 views
Changing compression in memory
I have some large files that I need to change the compression type of for input to a program--I need to unrar them and then gzip (or bzip2) them. However, they're highly compressed files and I don't ...
-1
votes
2answers
83 views
How to compress with bzip2 and gzip using xar?
In the "Why Xar" page of the Xar Google Code page it says:
Additionally, this means xar can use different compression methods for each file in the archive. For instance, it might not be a good ...
2
votes
1answer
95 views
Backing Up to a Compressed Archive on Linux
How would you go about backing up just some files and subdirectories of a given directory to a compressed archive so that the tree structure could then easily be recreated from that archive.
...
1
vote
1answer
858 views
What's the difference between gunzip and unzip?
What is the difference between gunzip and unzip? Tried to search but couldn't find anything relevant with this.
2
votes
1answer
758 views
Clear unused space with zeros (btrfs)
How to clear unused space with zeros ? (btrfs)
I'm looking for something smarter than
cat /dev/zero > /mnt/X/big_zero ; sync; rm /mnt/X/big_zero
Like FSArchiver is looking for "used space" and ...
8
votes
2answers
2k views
Clear unused space with zeros (ext3,ext4)
How to clear unused space with zeros ? (ext3,ext4)
I'm looking for something smarter than
cat /dev/zero > /mnt/X/big_zero ; sync; rm /mnt/X/big_zero
Like FSArchiver is looking for "used space" ...
3
votes
1answer
203 views
Best compression of similar files?
I've got a few full old backups of things like binary database dumps. Obviously, they don't differ much so doing full backups is not the smartest idea here. For now, I'm looking for a compression ...
5
votes
2answers
3k views
Is it possible to compress a very large file (~30 GB) using gzip?
Is it possible to compress a very large file (~30 GB) using gzip? If so, what commands, switches, and options should I use?
Or is there another program (preferably one commonly available on Ubuntu ...
2
votes
1answer
602 views
unrar part of a multipart rar file
Suppose you have a multipart rar file, say file.part1.rar, file.part2.rar, file.part3.rar.
I know that I can extract only the first parts using for example
unrar e -kb file.part1.rar
However ...
7
votes
2answers
4k views
Is it possible to mount a gzip compressed dd image on the fly?
I like create an image backup for the first time I'm backing up a system. After this first time I use rsync to do incremental backups.
My usual image backup is as follows:
Mount and zero out the ...
8
votes
3answers
4k views
How to XZ a directory with TAR using maximum compression?
So I need to compress a directory with max compression.
How can I do it with xz? I mean I will need tar too because I can't compress a directory with only xz. Is there a oneliner to produce e.g. ...
5
votes
2answers
9k views
How can I reduce a video's size with ffmpeg?
How can I use ffmpeg to reduce the size of a video by lowering the quality (as minimally as possible, naturally, but I need it to run on a mobile device that doesn't have much available space)?
I ...
8
votes
2answers
1k views
How to create a tar.gz file from a folder excluding a folder
How do I exclude a file or folder while creating a tar.gz file with tar command?
2
votes
1answer
2k views
Zip everything in current directory
I'd like to compress and package everything, including files and folders in current directory, into a single ZIP file on Ubuntu.
What would be the most convenient command for this (and name of the ...
3
votes
2answers
262 views
Compressed filesystem inside a file in Linux
I have a flash drive which is FAT32 formatted. I want to put a linux filesystem on the drive inside a file. I know I can do this by creating a file and formatting is with ext3 (or any other file ...
4
votes
3answers
296 views
Is there a command to list the compressed file sizes for files within a .zip file?
I'd like to see the absolute size in bytes of each file that has been compressed into single zip file. Having read the zip man page, I'm not sure that that utility can do it. This is on Mac OS X.
...
4
votes
1answer
300 views
Appending checksum information to file
I'd like to embed checksum information into file, that I transfer.
It's tar.gz or tar.xz file and I can only transfer one file to remote side.
How do you recommend I embed checksum information?
I ...
