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Thread: What does the "../../" mean?

  1. #1
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    What does the "../../" mean?

    Hello,

    I have seen "cp -r ../../PATH/". What does the "../../" mean?

    I have searched but cannot find an answer.

    Thanks!

  2. #2
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    Re: What does the "../../" mean?

    ../ refers to the parent of the current directory. ../../ refers to the parent of the parent. For instance,

    Code:
    cd /usr/share/dpkg
    ls ../     # returns the directory listing for /usr/share
    ls ../../  # returns the directory listing for /usr
    The current directory can be represented as a single dot. Both it and .. will appear in a directory listing if you use "ls -la".
    Last edited by SeijiSensei; August 1st, 2019 at 09:29 PM.
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  3. #3
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    Re: What does the "../../" mean?

    In all popular computer operating systems, there is an idea of
    a) absolute paths
    b) relative paths

    Absolute paths begin with a / or whatever the directory separator might be. In general, a / can be used, even on Windows.
    Let's use your HOME directory as an example. Assuming you didn't do anything funny, and your username is littleejido, then your HOME directory will be in
    /home/littleejido that is the absolute path to it.

    If your current working directory is /home, cd /home will get you there, then cd littleejido will take that specific shell/CLI/terminal into your HOME using a "relative path." You could have used cd ./littleejido too, which is also a relative path.

    Moving on. You can get into your HOME for the current userid using any of these commands:
    Code:
    cd $HOME
    cd ~
    cd ~/
    cd ~littleejido
    all the same result. If you are littleejido and want to get into userid's "joe" HOME and you are inside your HOME, then you can use,
    Code:
    cd ~joe
    cd ../joe
    cd /home/joe
    cd ../../home/joe
    Clear as mud?

    Being able to use relative paths can really save time typing.

    If there are only 2 userids on the computer, joe and littleejido, and you are logged in as littleejido and inside littleejido's HOME, you can get into joe's HOME using some wildcards too.
    Code:
    cd ~joe
    cd ../j*
    cd /ho*/*e
    cd ../../ho*/j*
    The pattern used just needs to be unique enough to match 1 solution.

  4. #4
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    Re: What does the "../../" mean?

    It's what is called a 'relative' path and it's doing what the previous post have explained. It's an alternative to an absolute path which will list all parent directories. If you are familiar with HTML I believe the same convention is used to address links, images, and files. If you are not familiar with HTML just know this convention is used widely in markup and programming languages and not just in a bash terminal.

    Now that I think of it, why does the convention uses two dots rather than just one?
    Last edited by an-ordered-hole; August 3rd, 2019 at 10:13 PM.

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    Re: What does the "../../" mean?

    Quote Originally Posted by an-ordered-hole View Post
    Now that I think of it, why does the convention uses two dots rather than just one?
    Because ./ is the current directory, so ../ is the parent.

    This convention has been around since 1970 and pretty much every popular OS that isn't a mainframe uses it, including Windows. In fact, in Windows, you can use cd ../../ instead of cd ..\..\ if you like - as a cross-platform software developer, we used this all the time in our code that ran on over 12 platforms.

    Some shells, like zsh, support just adding dots to go up one more level. https://stackoverflow.com/questions/...in-zsh-like-cd

    Of course, you can create aliases in bash to do it that way too:
    Code:
    alias cd...='cd ../../../'
    alias cd....='cd ../../../../'
    Notice that my aliases don't have spaces ... so they appear as a command.
    Last edited by TheFu; August 4th, 2019 at 01:02 AM.

  6. #6
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    Re: What does the "../../" mean?

    Interesting. Also, if you run the
    command(lists all files in current directory):
    ls -la

    output:
    drwxr-xr-x 31 hegel hegel 4096 Aug 3 20:49 .
    drwxr-xr-x 3 root root 4096 May 8 20:10 ..
    The first two directories are . & .. and does that mean they are actual files. Like can you delete or change the name of '.'? Or are they just relative names?
    Last edited by an-ordered-hole; August 4th, 2019 at 05:56 PM.

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    Re: What does the "../../" mean?

    I think the OP's question was answered. Start your own thread if you have a question. Thread hijacking is to be avoided here.
    In the meantime, you can look up "everything is a file" in wikipedia.

  8. #8
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    Re: What does the "../../" mean?

    1. The guy has not stated he's satisfied with the answers

    2. Adding context to the original question serves to broaden understanding. No question can be categorically answered by one person in a few posts.

    3. You're extremely unfriendly/trolly.

    Pretty sure you are to be avoided here.
    Last edited by an-ordered-hole; August 8th, 2019 at 03:16 AM.

  9. #9
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    Re: What does the "../../" mean?

    Hello an-ordered-hole, if you have an answer then you are more then welcome to post it, if you have a question then you need to start your own thread as it gets confusing for the users being helped and the volunteers helping, TheFu is one of the most helpful volunteers here and we do not allow derogatory remarks about other members here, please read the forum rules here:

    https://ubuntuforums.org/misc.php?do=showrules

    If you have an issue with a post please use the report button in the lower left hand corner of he post to report it.

  10. #10
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    Re: What does the "../../" mean?

    This is all pretty well answered above . . . the following is strictly opinion and take it as you wish. I'd just like to add in scripting of almost any language I find this usage annoying. Larry Wall calls this "dot-toothpick" syntax and proposes lots of ways to avoid it in Perl, but his concepts apply to almost any scripting language.

    Why do you find it annoying?

    Developers spend most of their time scanning files, following code, every little thing we have to stop and think about is pretty much a waste of time. Wrangling with "where am I, and where is this telling me to look?" is tedious and often time consuming when I should be spending the time, well, coding.

    Second, if you ever need to move A Thing you have to find all the directory references and update them. Then fix them when you get the dots and toothpicks wrong.

    Last, there are so many better ways to deal with directory traversal. Among them are setting environment variables defining paths (either system wide or app specific,) set down the rule to always start from root (absolute for CLI, domain-relative from HTTP,) or even better, use autoloaders and namespacing so you never have to figure out the dot-toothpicks ever again.

    Just IMO

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