Tagged Questions

The tag has no wiki summary.

learn more… | top users | synonyms

1
vote
0answers
67 views

problem with /compress

I have script that was provided with some SW. The script output is something like that (in debug mode). + changeDirectory + '[' -d /cdr/work/proc_raw/proc ']' + cd /cdr/work/proc_raw/proc + echo ...
-2
votes
1answer
123 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 | ...
9
votes
3answers
1k 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
829 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
2k 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
388 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
140 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 ...
1
vote
3answers
4k 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
vote
1answer
2k views

Trying to compress avi file using ffmpeg

I used the command below to compress an avi file(using ubuntu) ffmpeg -i input.avi -vcodec msmpeg4v2 output.avi but I am getting these errors Incompatible sample format 's16' for codec 'ac3', ...
0
votes
2answers
496 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 ...
6
votes
1answer
2k 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 ...
3
votes
3answers
541 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
2k views

Uncompress txt.gz files [closed]

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
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
69 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
145 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
184 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
4k 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
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 ...
18
votes
4answers
13k 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
497 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
3answers
11k 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 ...
23
votes
5answers
17k 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 ...
30
votes
4answers
19k 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. ...
13
votes
1answer
33k 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 ...
10
votes
2answers
4k 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?
6
votes
1answer
9k 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
650 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 ...
5
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
670 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
335 views

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

Is there anything like CompCache for FreeBSD?
1
vote
1answer
2k 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
85 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
13k 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 ...
5
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?
10
votes
2answers
3k 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
46 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
1k 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
327 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
2k 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
205 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 ...