Why do TAR files always need to be decompressed twice?

[Keith Barrow]

dingdingdingdingding!!!!!! We have a winner!!!!

KeithBarrow.net[^] - It might not be very good, but at least it is free!

[hevisko]

I must agree, kids these days have all these slang wordings on phones, but can't grok that tar stands for TApe aRchive, i's jst s bvius.

[Bob1000]

luxury! Solder bits of wire!

[Peter Adam]

For first, you compare part of the file system to a file system. Second, NTFS is more inode than inode itself, as it stores the file data itself as attribute. Third, for Windows there is NTFS since 1993. In the Unix world since we have seen at least half dozen über weltmeister open source, free as in freedom file systems, every one leaving everything else in the dust. So much about extensibility and stability.

[svella]

megaadam wrote: tar xvf file Does both in one comnand Wrong - you need

tar xvfz file

[kalberts]

Don't make fun of us oldies! Sure, it was back in the summer of 1978, before I started my studies, I got a summer job in a company where you had to flip switches, deposit, flip switches, deposit... I believe that mini bootstrap was 12 or 14 instructions long, enough to read in the short paper tape with the real bootstrap, so that we could mount the large reel of paper tape with, say, the compiler. For the system software, like the boot, it really wasn't paper, it was either mylar (I never met one who could tear off one of those mylar tapes with his bare hands), or plastic covered aluminum with so sharp edges that it could cut your throat if it got out of control. Some operators used leather gloves as a protection. But they never wore out, even if read a dozen times every day. On the other hand: If you were lucky enough to need the same program the next morning that you used last the previous day, you didn't have to reload it: The machines had real core memory that retained its contents even if you turned off the power. (One of the guys scoffed semiconductor RAM, insisting that it was a fad: Computer industry will never accept memory that requires power to be constantly on to retain its contents!) I even flipped switches at the University, but that was in a more specialized context: In one lab exercize we used a 2901 development kit. 2901 was a widely used 4 bit bit slice processor, that you could line up in twos for an 8 bit CPU, four for a 16 bit CPU, eight for a 32 bit CPU. It contained the hard logic, which was controlled by an external microcode RAM. For our lab, we had a 16 bit by 64 words RAM, and we wrote the microcode to read two 4 bit input values and place the sum on the output. Really knowing what's going on, all the way down to the signal paths, is impossible with the systems of today. Even understanding the operating system thorougly, software only, is out of reach. I must admid that I sometimes long back to those days when everything could be understood, you had a feeling of mastering it all, you never left anything to automagic mechanisms you would simply have to trust in blind faith. The nearest you'll get today is in embedded programming, coding plain C on, say, an ARM M0. I did that for a few years, and it felt as if nostalgia had turned real :-)

[kalberts]

I wonder how much slang has been influenced by Unix (or *nix, if you prefer). Before *nix, slang made some degree of sense to me, but then we got these absurdities like 'less' for displaying av file (yes, I know its history!), GNU, and a thousand 'funny' but made-up and totally meaningless (in the way they are used) names and terms. I see more and more of that creeping into non-computer slang as well: terms with no etymological background related to the application, but with a completely unrelated meaning that is absurd in the context. Controlling the development of a natural language makes herding cats look like a task for five year olds.

[Joop Eggen]

The decompression can be combined, but indeed the format packed twice as .tar.gz or `.tar.bz2` or such. This is à la Unix where small operations are combined into on large operation. Its advantage here: tar (tape archive) concatenates all files, and the ensuing gz compression can do a "far" better compression over all content. As opposed to .zip compression.

[bleahy48]

You need one of these new-fangled magnetic drum memories!

[vtokar]

Didn't you miss z?

[rjmoses]

Let's not forget that a fundamental thought in Unix was small, individual programs strung together through pipes and stdin/stdout redirection. So: find . -print |grep "draw" | grep "\.c$" |tar -c -T - |gzip -c > temp.tar.gz is an elaborate way (albeit inefficient) of finding all files ending in ".c" in the current directory and all subdirectories that contain "draw" as any part of the file name to create a tar file which is then zipped to stdout to a file named "temp.tar.gz" The point here is demonstrate hooking together small programs through piping. So, because they probably found that many tar files got zipped, someone got the idea of combining zip into the tar command through "tar -cvfz temp.tar.gz filelist". A good idea.