Re: Why does the command builtin not circumvent invocation of builtins?

Hi,

On 30/08/2024 19:28, Anselm Schüler wrote:
> The dash(1) manpage reads:
> 
> command [-p] [-v] [-V] command [arg ...]
>         Execute the specified command but ignore shell functions when 
> searching for it. (This is useful when you have a shell function with 
> the same name as a builtin command.)

This implies that it does not ignore builtin commands, because otherwise 
it would not be useful for this purpose.

> Because of this, I expected commands like command . or PATH= command 
> true to fail. They don’t.

. and true are builtin commands, not shell functions (at least not by 
default), so they are found.

This is how it is meant to work. The parenthesised comment is there to 
highlight that you can do things such as

   echo() {                  # shell function
     command echo "$@" >>log # builtin command
     command echo "$@"       # builtin command
   }
   echo hello # call shell function to print both to log and to stdout

(Mind you, this is an intentionally silly example that nobody should 
write this way, it just demonstrates the concept.)

Here, it is important for "command echo" to find the builtin command, 
not the shell function. If it found the shell function, this would 
recurse infinitely. If it did not find the builtin command, this would 
not necessarily print anything.

This also matches how "command" works in other shells as well.

Cheers,
Harald van Dijk