Re: odd behavior from overloading the "source" builtin

[Chris F.A. Johnson]

On Sun, 16 Mar 2014, Doug McIlroy wrote:

> GNU bash, version 4.2.39(1)-release (x86_64-redhat-linux-gnu)
> interprets this shell script differently when bash input comes 
> from a terminal or when it conmes from a file:
>         source(){
>         echo x
>         }
>         source
> In the former case it prints x; in the latter it gives a
> missing-filename diagnostic, presumably from the builtin "source".
> The behavior is independent of whether the environment
> contains "source()".

> The bash man page leads me to expect the former behavior
> because commands are said to be looked up first among
> shell functions, then among builtins.

> The behavior seems to be peculiar to "source". If "source"
> is replaced by "wait, the difference vanishes.

   I get the same behaviour whether entered in a terminal or executed
   in a script (bash 4.2 and 4.3).

$ source(){
  echo x
}
$ source
x
$ xx.sh
x