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Matt Randolph wrote: |
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|
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> Matt Randolph wrote: |
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> |
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>> |
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>> This may be a case of a different paradigm being used by 7-zip than |
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>> that used by traditional (*nix) compression tools. If my memory |
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>> serves me, the 7-zip format is very similar to the pkzip format in |
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>> its usage. By that I mean that one is not required to make a tarball |
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>> before compressing multiple files. The format allows you to skip the |
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>> tar step and make an archive consisting of whichever files and |
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>> directories you wish. |
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>> |
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>> The problem, I'm guessing, is that the 7-zip archive format was |
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>> developed in the Windows world where users and groups and permissions |
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>> have no meaning (I think that has changed or is changing in the NT/XP |
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>> world, but I don't know and don't especially care). Hence, these |
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>> attributes aren't accomodated by this format. I assume the 7-zip |
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>> extractor program sets the user and group of the extracted files to |
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>> that of whomever extracts them. |
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>> |
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>> What everyone has rightly pointed out, namely that you can make a |
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>> tarball and then compress that, is exactly right. That IS how one |
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>> would use 7-zip with a proper operating system. |
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>> |
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>> The original poster most likely used the 7-zip archiver as a |
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>> stand-alone tool, rather than using it in conjunction with tar. This |
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>> is not altogether surprising as one typically compresses a directory |
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>> with a single tar command (and an implied pipe) rather than |
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>> explicitly piping the output of tar to the compression utility. |
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>> Since there is no --7-zip switch in tar, the OP couldn't simply 'tar |
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>> -7cf backup.tar.7zip lib/'. The OP probably simply 7-zipped his |
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>> directory without tarring it first and consequently ran into the |
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>> limitations of the archive format. |
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>> |
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> "-rw-r--r-- 1 root root 3536665 Aug 13 00:01 backup.tar.7z" |
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> |
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> Oops! I should read more carefully. |
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> |
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In an effort to put this matter to rest (and to save a little face), I |
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have tested 7-zip. |
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I created a directory containing two empty files. These files were then |
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assigned arbitrary users and groups. Next I created a tarball of the |
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directory. I changed the ownership of the tarball too. Finally, I |
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7-zipped the tarball. |
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When I extracted the tarball it was given the user and group of the |
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extractor (eg. myusername:users) rather than what it was assigned |
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above. When I untarred the tarball, however, the contents were exactly |
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as you would expect; they had the user and group settings that I |
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assigned them previously. |
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|
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I once again feel that my original hypothesis is essentially correct. |
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7-zip doesn't support user, group and permission data because it was |
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originally developed for Windows. But this is a limitation that can be |
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worked around by making a tarball first. The OP noticed that the |
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ownership and permissions of the tarball changed and made a comment |
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about that. This fact has little relevance for most users since we will |
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only care about the contents of the tarball, not the tarball itself. |
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-- |
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