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Yeah, a handful of these tripped me up as well. I got: Question: Write the command that you use to move into your home directory '~' Your answer: cd Correct

Yeah, a handful of these tripped me up as well. I got: Question: Write the command that you use to move into your home directory '~' Your answer: cd Correct answer: cd ~ The man pages specify that cd moves into the current user's $HOME directory if called without arguments, but I'm sure there's some mystic difference between cd $HOME and cd ~ in certain cases.

maherdeeb 7y ago
Thanks a lot for your comment. I think both answers are correct. I am not sure if cd works for all systems.
- codetrotter 7y ago
  https://pubs.opengroup.org/onlinepubs/9699919799/utilities/cd.html https://pubs.opengroup.org/onlinepubs/9699919799/utilities/c... cd without an argument will change directory to $HOME if $HOME is set and the value is non-empty as defined in the standard linked above. That’s not to say that all Unix-like systems do or even try to implement everything of that standard, but it’s a good indicator pointing to that a lot or most of them probably do. As for cd ~, tilde expansion is done by the shell, not by cd. Same goes with any other command that you type ~ as the leading part of a path and provide as argument. (Also, in bash, among others, cd is a builtin command.) The shell will substitute the ~ for the path of your home dir when ~ is alone or followed by a slash and anything else. (And you probably know also that ~example would refer to the home dir of a user named “example”.) I think you will sooner run into a system with a shell that doesn’t do tilde expansion, than you will run into a Unix system where plain cd without an argument doesn’t bring you to your home dir.
  - pushpop 7y ago
    Technically the chances of tilde not working are the same as cd behaving differently because they’re both shell builtins. I’m guessing (though admittedly not checked) that both ~ and cd (without parameters) are defined in POSIX. In which case any edge case that doesn’t conform could reasonably be discounted with regards to the submission’s exercise.
    - pushpop 7y ago
      I did some quick research on the POSIX thing and it looks like cd (without parameters) is defined in POSIX: https://www.unix.com/man-page/posix/1posix/cd/ https://www.unix.com/man-page/posix/1posix/cd/ Also I don’t know why many of my posts keep getting downvoted even when they’re factually accurate.
- montag 7y ago
  Things like this should probably be ‘Correct’ with a small warning.
  - chrismorgan 7y ago
    Why warn? It’s perfectly reasonable behaviour to learn. I’ve used it for years.
DaveInTucson 7y ago
Not sure if the site is meant to be strictly Linux/Unix or not, but on Windows, cd without any path just prints the current directory and doesn't do anything else. (Although "cd ~" produces the response "The system cannot find the path specified.")

maherdeeb 7y ago

Thanks a lot for your comment. I think both answers are correct. I am not sure if cd works for all systems.

codetrotter 7y ago
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/cd.html https://pubs.opengroup.org/onlinepubs/9699919799/utilities/c... cd without an argument will change directory to $HOME if $HOME is set and the value is non-empty as defined in the standard linked above. That’s not to say that all Unix-like systems do or even try to implement everything of that standard, but it’s a good indicator pointing to that a lot or most of them probably do. As for cd ~, tilde expansion is done by the shell, not by cd. Same goes with any other command that you type ~ as the leading part of a path and provide as argument. (Also, in bash, among others, cd is a builtin command.) The shell will substitute the ~ for the path of your home dir when ~ is alone or followed by a slash and anything else. (And you probably know also that ~example would refer to the home dir of a user named “example”.) I think you will sooner run into a system with a shell that doesn’t do tilde expansion, than you will run into a Unix system where plain cd without an argument doesn’t bring you to your home dir.
- pushpop 7y ago
  Technically the chances of tilde not working are the same as cd behaving differently because they’re both shell builtins. I’m guessing (though admittedly not checked) that both ~ and cd (without parameters) are defined in POSIX. In which case any edge case that doesn’t conform could reasonably be discounted with regards to the submission’s exercise.
  - pushpop 7y ago
    I did some quick research on the POSIX thing and it looks like cd (without parameters) is defined in POSIX: https://www.unix.com/man-page/posix/1posix/cd/ https://www.unix.com/man-page/posix/1posix/cd/ Also I don’t know why many of my posts keep getting downvoted even when they’re factually accurate.
montag 7y ago
Things like this should probably be ‘Correct’ with a small warning.
- chrismorgan 7y ago
  Why warn? It’s perfectly reasonable behaviour to learn. I’ve used it for years.

DaveInTucson 7y ago

Not sure if the site is meant to be strictly Linux/Unix or not, but on Windows, cd without any path just prints the current directory and doesn't do anything else. (Although "cd ~" produces the response "The system cannot find the path specified.")