Ignored shell name in language identifier

[stessaris]

Shell name in language identifier doesn't seem to be used in most of the cases, reverting to default shell. I observed it in vscode (vscode 1.107.1 and vscode-runme 3.16.0) and command line. The odd thing is that within vscode terminal, the cli version works as expected (see below); so it must be something related with the environment. Any suggestion for further tests?

Using the following markdown file for testing the shell:

```sh { name="Sh" }
echo "Using:" `ps -o comm='' -p $$`
```

```bash { name="Bash" }
echo "Using:" `ps -o comm='' -p $$`
```

```zsh { name="Zsh" }
echo "Using:" `ps -o comm='' -p $$`
```

```ksh { name="Ksh" }
echo "Using:" `ps -o comm='' -p $$`
```

CLI in terminal

Default shell

❯2❯ printenv SHELL
/bin/zsh

❯2❯ runme run --all --allow-unnamed --skip-prompts --filename=which_shell.md
 ►  Running task "Sh"...
Using: /bin/zsh
 ►  ✓ Task "Sh" exited with code 0
 ►  Running task "Bash"...
Using: /bin/zsh
 ►  ✓ Task "Bash" exited with code 0
 ►  Running task "Zsh"...
Using: /bin/zsh
 ►  ✓ Task "Zsh" exited with code 0
 ►  Running task "Ksh"...
Using: /bin/ksh

 ►  ✓ Task "Ksh" exited with code 0

Changing the SHELL env variable:

❯2❯ SHELL=/bin/bash runme run --all --allow-unnamed --skip-prompts --filename=which_shell.md
 ►  Running task "Sh"...
Using: /bin/bash
 ►  ✓ Task "Sh" exited with code 0
 ►  Running task "Bash"...
Using: /bin/bash
 ►  ✓ Task "Bash" exited with code 0
 ►  Running task "Zsh"...
Using: /bin/bash
 ►  ✓ Task "Zsh" exited with code 0
 ►  Running task "Ksh"...
Using: /bin/ksh

 ►  ✓ Task "Ksh" exited with code 0

vscode

With the Run Block button:

In "notebook" mode:

CLI in vscode terminal

Oddly enough, within the vscode terminal it works as expected:

[sourishkrout]

Hi @stessaris,

The way you coerce a shell is different. The language identifier is primarily to classify the code block's language, not necessarily it's interpreter. We do attempt some auto-detection though: https://docs.runme.dev/usage/shebang#list-of-auto-detected-language-runtimes.

As per the docs, you'd either use document-level (frontmatter) or the cells to set the interpreter. Either via the Configure button in VS Code or directly in the markdown, such as:

Per cell

```sh { name="Sh" interpreter=sh }
echo "Using:" `ps -o comm='' -p $$`
```

```bash { name="Bash" interpreter=bash }
echo "Using:" `ps -o comm='' -p $$`
```

```zsh { name="Zsh" interpreter=zsh }
echo "Using:" `ps -o comm='' -p $$`
```

```ksh { name="Ksh" interpreter=ksh }
echo "Using:" `ps -o comm='' -p $$`
```

For the entire document using frontmatter

---
shell: ksh
---

```sh { name="Sh" }
echo "Using:" `ps -o comm='' -p $$`
```

```bash { name="Bash" }
echo "Using:" `ps -o comm='' -p $$`
```

```zsh { name="Zsh" }
echo "Using:" `ps -o comm='' -p $$`
```

```ksh { name="Ksh" }
echo "Using:" `ps -o comm='' -p $$`
```

There's a chance that the CLI attempts to "fallback" to look up the identifier as interpreter. I'd have to dig through the code to be sure. Lemme know if this helps, please, @stessaris.

[stessaris]

Thanks for your reply @sourishkrout, I understand that the language runtime can be forced with the interpreter property. What's confusing me is that in the docs bash, zsh, and ksh are among the "auto-detected runtimes", but it reverts to the SHELL environment variable in most of the cases. It's also strange the inconsistent behaviour across environments and the fact that ksh is the only one that's correctly detected in most of the cases.

I'll use the interpreter property to ensure the runtime; I stumbled on the problem because I was using a bash feature and got an error because it was running with zsh. Maybe's worth mentioning it in the documentation to avoid these errors; e.g. when people use shells that could behave quite differently from the common POSIX shells (e.g. nu or pwsh).