Command execution

Command execution

[aismtnt]

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Documentation: https://zsh.sourceforge.io/Doc/Release/Command-Execution.html

There is a statement in docs:

'If execution fails because the file is not in executable format,and the file is not a directory, it is assumed to be a shellscript. /bin/sh is spawned to execute it.'

I wonder if it's true or maybe I'm missing something.

My understanding is that if I create a file with shell commands but won't change its mode to executable, it will still be executed, because it is assumed to be a shell script.

But it does not.

```zsh
# Create file.
echo 'echo "Hello world"' > my_script

# Run file.
my_script
zsh: command not found: my_script
```

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Re: Command execution

[Mikael Magnusson]

On 11/15/21, aismtnt@tutanota.com <aismtnt@tutanota.com> wrote:
>
> Documentation:
> https://zsh.sourceforge.io/Doc/Release/Command-Execution.html
>
> There is a statement in docs:
>
> 'If execution fails because the file is not in executable format,and the
> file is not a directory, it is assumed to be a shellscript. /bin/sh is
> spawned to execute it.'
>
> I wonder if it's true or maybe I'm missing something.
>
> My understanding is that if I create a file with shell commands but won't
> change its mode to executable, it will still be executed, because it is
> assumed to be a shell script.
>
> But it does not.

"executable format" refers to the contents of the file, eg will the
kernel exec()ute this, and "executable mode" refers to the mode of the
file, they are not the same thing. The quoted statement only applies
if execution failed because of the file contents not being a valid
executable format, but in your case the execution failed because of
missing permissions (earlier check), so the statement does not apply.

-- 
Mikael Magnusson

Re: Command execution

[Roman Perepelitsa]

On Mon, Nov 15, 2021 at 2:33 PM Mikael Magnusson <mikachu@gmail.com> wrote:
> [...] in your case the execution failed because of
> missing permissions (earlier check)

It didn't get that far: "command not found" error implies a failed
search in PATH.

  % echo 'echo "Hello world"' >my_script

  % my_script
  zsh: command not found: my_script

  % path+=($PWD)
  % my_script
  zsh: permission denied: my_script

  % chmod +x my_script
  % my_script
  Hello world

Roman.