Lol, I have an alias for cd on my system, which uses chdir otherwise it
would loop.
I'm using tcsh. It turns out chdir is just a synonym for cd built into tcsh.
I knew What would happen if you did a sudo cd, but I was so focused on
finding another way to type in cd I completely forgot about it. Oops
On Tue, Dec 20, 2022, 11:54 PM Rusty Carruth via PLUG-discuss <
plug-discuss@lists.phxlinux.org> wrote:
> Well, what exactly are you trying to do? Even if you could do 'sudo cd
> directory', simply executing that command will result in NOTHING
> HAPPENING with respect to your next command. Lets dig in to it at the
> end of the message, but for now trust me.
>
> Oh, and the shortest answer, the conclusion/solution, is at the end, so
> if your eyes start to glaze over as you read the below, jump to the bottom.
>
> First, see what the permissions on <path> is/are. Try 'ls -ld <path>'.
> If you get Permission denied, and path includes '/', then somewhere
> along the path (ha) your permissions don't let you do a directory
> listing. If you see something like this:
>
>
> drwxrwxrw- 6 rusty rusty 4096 Dec 19 16:22 <path>
>
>
> and you are not rusty nor in group rusty, then you can't do a directory
> listing of <path>
>
>
> (That (missing!) 'x' there is the key to your (not) being able to see
> the contents. It enables 'search' for directories, which is what you
> need to be able to see in to, or cd into, the directory)
>
>
> If any directory on the <path> does not have x set for you, then you
> can't see in to it and get permission denied.
>
>
> Now, why are both 'sudo cd foo' and 'sudo chdir foo' totally useless?
> (even if you COULD do it! Which you can't! See below the below for
> news about 'chdir')
>
>
> Well, when you type 'sudo' and are successful (to perhaps muddy the
> water a bit - which is to say you have permission to run a command as
> root using sudo), the shell starts a NEW shell, running as root, which
> executes your command and then, when that command completes exits back
> to the shell which started it. So, let's say your shell's PID is 123.
> You type sudo cd foo, the shell starts a NEW shell,say PID 321, which
> does the cd and then exits back to the shell that started it, PID 123.
> Where the 'current working directory is still wherever you were before
> you typed 'cd'!
>
> A lot of typing and process running to do absolutely nothing!
>
>
> However, 'chdir' is not a command at all. Try it:
>
> === shell interaction begins
>
> Tue Dec 20 23:19:09 RustyC ~/class $ chdir foo
>
> Command 'chdir' not found, did you mean:
>
> command 'hdir' from deb hfsutils (3.2.6-14)
> command 'cdir' from deb cdtool (2.1.8-release-7)
>
> Try: sudo apt install <deb name>
>
> Tue Dec 20 23:19:35 RustyC ~/class $
>
> === shell interaction ends
>
> (cdtool has a 'cdir', but it 'lists information about the currently
> loaded audio compact disc', doing nothing w.r.t. current working dir)
>
> Nope, all you get is 'cd', which as they say, is a shell builtin. Now,
> WHY is it a shell builtin? Because your 'current working directory' is
> *set* and *maintained* by the shell. Changing directory inside a program
> will not affect the 'current working directory' of the shell that
> started the program (unless there happens to be a hook in bash you can
> call from your program, which is possible, I suppose, but I've never
> heard of it. And, no chdir(2) does not, I believe, affect the shell
> which started the process which called chdir).
>
>
> Now, let's keep beating this dead horse, shall we?
>
>
> Back to the original question, and the meta-question above it, which is
> sort of 'how should I debug this sort of thing?'
>
> The first huge hint is 'permission denied'. This means that the user
> executing the command does not have (file system) permission to do
> whatever it is they tried to do (I'm speaking here of when a command is
> doing something w.r.t. a file. Doing 'sudo ' and getting 'Permission
> denied' does not have anything (really) to do with file permissions, so
> isn't involved here).
>
> So, how do you debug this? The first thing you should do is a long
> directory listing of the file that complained (always use 'ls -ld' for
> this). If that gets permission denied, then remove the last 'thing' in
> the path and re-do the ls -ld. Inspect the permissions (the rwxrwxrwx
> things) and the owner/group. If you are the owner, then look at the
> first 3 permission bits. If you are NOT the owner, but you are IN the
> group, look at the next 3. If you are neither the owner nor IN the
> group that owns the file, then look at the last 3. To change in to a
> directory you need execute permissions (you can, in fact, 'cd' into a
> directory that you do not have read permissions to! But, of course, you
> can't see anything in it! Try it. 'mkdir foo;chmod 100 foo;cd foo;ls -l').
>
>
> So, after much ado, we have finally come to the conclusion that some
> directory in 'path' does not have the 'x' permission for you set.
>
> Fix that, you be good.
>
> Rusty (yes, I do sometimes teach a class on Linux, why do you ask? ;-)
>
> On 12/20/22 18:27, Keith Smith via PLUG-discuss wrote:
> >
> >
> > Hi,
> >
> > Not sure what is going on here:
> >
> > cd <path> results in message "-bash: cd: <path> : Permission denied".
> >
> > Then I add sudo : sudo cd <path> results in message : "sudo: cd:
> > command not found".
> >
> > Any help is much appreciated!!
> >
> > Keith
> > ---------------------------------------------------
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