using sudo inserts '[' before command

[willem_mint]

Okay, weird and annoying issue.
Whenever I use any command with sudo, an opening bracket character is inserted before the command.
This causes an 'unknown command' response, after which the command is executed anyway.
This causes havoc when chaining commands.

eg.

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$ sudo mkdir test

results in (translated into English by me)

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unknown command '[mkdir]', did you mean: 
 command '[mkdir]' in deb coreutils (8.30-3ubuntu2) 
 (... and so on)

then it just promps for password and after authorisation just goes ahead and executes the command.

Anyone have any idea what could be causing this?

Mint v 20.3 64b
Cinnamon v 5.2.7,
bash v 5.0.17(1) release
Gnome Terminal 3.36.2

I don't know what other info might be relevant to the issue.

I'd appreciate any clue as to what's happening here.

[karlchen]

Hello, willem_mint.

Could you please share the complete terminal output of the commandline sudo mkdir test?
I.e. the commandline and everything which gets displayed? Not just some part.
And in this case, please, do not translate the output.
(If necessary I will manage to add the translation from Dutch to English. )

Could you also please share the output of this command: which sudo. - Reason for asking: I wonder a bit whether some script named "sudo" might be found following the $PATH variable, instead of the real "sudo" executable. Because "sudo" does not insert any characters into the commandline that follows "sudo".

Regards,
Karl

[Termy]

Might be worth running type sudo instead, in-case there's an alias or function overriding it, which which(1) won't pick up.

[willem_mint]

Hi Karlchen and Termy,

Thank you for your replies.

I do have nala installed, which I obviously should have mentioned in my first post. Sorry, it had been a long day when I posted that.

If I use type sudo I do see a condition that reroutes apt to nala, but that doesn't appear to insert anything...

Hello, willem_mint.

Could you please share the complete terminal output of the commandline sudo mkdir test?

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$ sudo mkdir test

Opdracht '[mkdir' niet gevonden, bedoelde u wellicht:

  opdracht 'hmkdir' van deb hfsutils (3.2.6-14)
  opdracht 'mkdir' van deb coreutils (8.30-3ubuntu2)
  opdracht 'mmkdir' van deb mblaze (0.6-1)

Probeer: sudo apt install <deb name>

[sudo] wachtwoord voor fam: 

Could you also please share the output of this command: which sudo.

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$ which sudo
/usr/bin/sudo

Might be worth running type sudo instead, in-case there's an alias or function overriding it, which which(1) won't pick up.

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sudo is een functie
sudo () 
{ 
    if ["$1" = "apt" ]; then
        shift;
        command sudo nala "$@";
    else
        command sudo "$@";
    fi
}

[Termy]

There we go. You have a function for sudo(8), and I see a typo in the code.

Replace:

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if ["$1" = "apt" ]; then

With:

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if [ "$1" = "apt" ]; then

Nice wee function though, especially by using the command builtin to avoid function recursion. The function is probably (but not necessarily) saved in '~/.bashrc', BTW.

An explanation for why you were getting that error: $1 (first positional parameter) would equal, in this case, mkdir, but you've prepended [ to mkdir, making [mkdir. Because of how if statements work in BASH, if is trying to test the exit status of an invalid and non-existent command [mkdir. Everything else on that line, after that word (shell's idea of a word), would be taken as arguments to the invalid command, hence you saw nothing about that, and the rest was likely ignored because of the syntax error. By adding the whitespace, BASH can now find a valid and existing mkdir(1) tool (usually in '/bin/mkdir'), allowing the statement to begin testing its exit status for the logic.

[karlchen]

Great tip the "type" command, Termy. It was the right track indeed.
And good catch, spotting the missing blank inside the if clause, which in the corrected form reads if [ "$1" = "apt" ]; then