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0answers
47 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
29 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
67 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
138 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
170 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. ...
4
votes
1answer
3k 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.
1
vote
1answer
2k views

Clear unused space with zeros (btrfs)

How to clear unused space with zeros ? (I am asking for tool for btrfs filesystem) I'm looking for something smarter than cat /dev/zero > /mnt/X/big_zero ; sync; rm /mnt/X/big_zero Like ...
15
votes
4answers
10k 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" ...
4
votes
2answers
455 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 ...
7
votes
2answers
9k 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
1k 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 ...
18
votes
5answers
14k 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 ...
26
votes
5answers
16k 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. ...
12
votes
1answer
28k 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 ...
9
votes
2answers
3k 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?
5
votes
1answer
7k 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
592 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
1k 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. ...
5
votes
1answer
604 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 ...
3
votes
1answer
303 views

Is there an in-memory compressed swap facility (like Compcache) for FreeBSD?

Is there anything like CompCache for FreeBSD?
1
vote
1answer
1k views

Updating tar.gz daily only with changed files [duplicate]

Possible Duplicate: Add/update a file to an existing tar.gz archive? I have some game files I wish to update daily and they create a tar.gz of the folder, but instead of making a full ...
1
vote
1answer
80 views

Can someone explain what hunzip is for?

I understand what hunspell is for, but I was browsing the source code and the man, and I'm not sure: Does hunzip compress text files or just dictionaries ?
8
votes
4answers
11k views

How to uncompress zlib data in UNIX?

I have created zlib-compressed data in Python, like this: import zlib s = '...' z = zlib.compress(s) with open('/tmp/data', 'w') as f: f.write(z) (or one-liner in shell: echo -n '...' | python2 ...
4
votes
2answers
2k views

What's the difference between tar.gz and tar.Z?

The downloads on this page, e.g. of NetCDF C/C++/Fortran 4.1.3, show tar.Z and tar.gz formats. The tar.Z doesn't even have a configure file in it. What is it used for?
9
votes
2answers
2k views

How can I view gzipped files in less without having to type zless?

I am using Ubuntu, and I would like to be able to type less compressed_text_file.gz and page the contents of the text file in uncompressed form. Is there a way to do this?
0
votes
1answer
45 views

Configure webserver for compression

Based on this page: http://code.google.com/speed/page-speed/docs/payload.html#GzipCompression I need to enable compression on my website, but I have no idea how to do this. If this is the right ...
4
votes
1answer
1k views

Does ssh compress connections in a tunnel individually?

I have one compressed SSH tunnel with one tunnel and multiple connections over it. Data in every connection tunneled is rather homogeneous, but compressing an interleaved stream will obviously make ...
5
votes
2answers
2k views

rsync-like tool that supports compression and maintains hardlinks?

I use an rsync-based backup scheme to maintain daily (and soon weekly and monthly as well) "snapshots" of my file server, using rsync's link-dest feature to store hardlinks between the snapshots for ...
6
votes
2answers
951 views

Why use cpio for initramfs?

I am making my own initramfs following the Gentoo wiki. Instead of the familiar tar and gzip, the page is telling me to use cpio and gzip. Wikipedia says that cpio is used by the 2.6 kernel's ...
1
vote
2answers
2k views

How do I turn on http compression?

I'm running a CentOS server and I want to save bandwidth, make pages faster, all that. How can I turn on http compression? Is it a module I enable for all sites? Can it be that simple?
3
votes
2answers
3k views

What Linux utility can split a large file into a multi-file archive that can be opened on Windows?

I have a 6GB file which I need to transport on DVDs. I have a Linux system, while the recipient has a Windows system. Is there any way for me to make a multi-part archive to spread the file across two ...
3
votes
4answers
326 views

Is there a way to redirect a file that is written

I have an application which I can not change, that writes to a big 250 GB plain text file. After compressing with GZ it is only 30 GB. This application has no option of compressing it's output, and ...
3
votes
1answer
1k views

initramfs image compression other than gzip

can the initramfs image be compressed by a method other than gzip, such as lzma?
7
votes
6answers
200 views

Is there any program to provide a consistent interface across multiple archive types?

At the moment, if I download a compressed file, it could be any of a .tar.gz archive, a tar.bz2 arhive, a .zip archive or a .gz archive. And each time I do so, I have to remember what the command line ...