• @SpaceNoodle
    link
    89
    edit-2
    1 year ago

    find “${HOME}/docs/”

    You want the full path in quotes so that paths with spaces are handled properly. Brackets are good practice when concatenating strings.

    • @Synthead
      link
      71 year ago

      If the strings don’t contain characters that help define a variable, like an underscore, how is it better practice to use curlies? It’s it just for consistency? Have you had any style guides or linters critique the use of variables without them?

      • @RazorsLedge
        link
        24
        edit-2
        1 year ago
        foo=ding
        foobar=dong
        
        echo \$foobar
        
        

        Brackets make it explicit what you’re trying to do. Do you want “dingbar” or do you want “dong”? I forget what the actual behavior is if you don’t use brackets here, because I always use brackets for this reason now

        • @subtext
          link
          51 year ago

          I believe the actual behavior here would be printing “dong” as the shell interpreter is greedy in its evaluation of variables.

          • @[email protected]
            link
            fedilink
            21 year ago

            the actual behavior here is to echo the literal string “$foobar”, because the $ sign is escaped. so no variable expansion will take place at all.

            • @RazorsLedge
              link
              21 year ago

              Oh lol. It doesn’t show the $ at all on my mobile app till I escaped it

              • @rtxnM
                link
                English
                11 year ago

                You should use markdown’s inline code (single `backtick`) and

                block code
                (triple backtick)
                

                tags. They are consistent across most markdown renderers (except Reddit’s, which uses four-space indentations (like, who the fuck thought that was a good idea?))

      • @SpaceNoodle
        link
        23
        edit-2
        1 year ago

        More than anything, I find that it’s a good habit to maintain in order to avoid simple mistakes. It also makes variables easier to spot in code and maintains consistency.

    • @[email protected]
      link
      fedilink
      English
      11 year ago

      This shit fucked me up so much when i was learning linux stuff. Especially cause a lot of my file paths had spaces. This is the way.

    • FuglyDuck
      link
      English
      1
      edit-2
      1 year ago

      “Concatenating”….

      …. That sounds either exceptionally painful or extremely fun.

      Quite possibly both…

  • @cttttt
    link
    111 year ago

    tl;dr - Second option usually.

    I think a huge part of shell programming (besides recognizing when anything more maintainable will do 😂😂😂) is trying to allow others who aren’t as familiar to maintain what you’ve written. Shell is full of pitfalls, not the least of which is quoting and guaranteeing how many arguments you pass to commands and functions.

    To me, the whole point of quoting here is to be crystal clear about where command arguments begin and end in spite of variable substitution. For this reason I usually go for the second option. It very clearly describes how I’m trying to avoid a pitfall by wrapping each argument to find in a pair of quotes: in this case, double quotes to allow variable substitution.

    Sometimes it’s clearer to use the first approach. For example, if the constant parts of one of those arguments contains a lot of special characters, it may make it clearer to use the first approach with the constant parts wrapped in single quotes.

    But even then there are more clear ways to create a string out of other strings. For example, the slightly slower, and more verbose use of printf and a variable, and then using that variable as an argument…wrapped in double quotes since it could contain special characters.

  • @DoomBot5
    link
    English
    81 year ago

    First one has the pitfall of a space at the end of the variable still causing it to fail.

    • @[email protected]
      link
      fedilink
      English
      119 days ago

      I don’t think this is correct. Consider what you see from using sh -c -- 'var="a " && printf "%s\n" "${var}"-z'

      If "${var}"-z resulted in two arguments instead of one, I’d see “a” and “-z” on different lines, but I see them on the same line, which means they are treated as a single argument.

      • @DoomBot5
        link
        English
        11 year ago

        It would still be considered a single variable because the entire string is quoted. The first scenario would have split it into 2 variables.

  • @Matriks404
    link
    11 year ago

    Bash has the worst syntax rules I have seen, and the fact that you can do both of these doesn’t help.

    I am probably going to switch to fish for any scripting, Python would probably be better, but it seems to be much more complicated and I am too lazy to learn it.