> For the complete documentation index, see [llms.txt](https://docs.ccv.brown.edu/bnc-user-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ccv.brown.edu/bnc-user-manual/xnat-to-bids-intro/bids-validation/oscar-legacy-validator.md).

# Oscar - legacy validator

⚠️ BIDS has [switched to a new BIDS Schema Validator 2.0](https://bids.neuroimaging.io/blog/2024/11/13/bids-validator-2.html), so these instructions are maintained for historical reasons only. You can find updated instructions for the new validator [in this previous section. ](/bnc-user-manual/xnat-to-bids-intro/bids-validation/oscar.md).

## 0. Summary of commands

```bash
version=v1.15.0
bids_directory=${HOME}/xnat-exports/bnc/study-demodat2/bids
simg=/oscar/data/bnc/simgs/bids/validator-${version}.sif
singularity exec --bind ${bids_directory}:${bids_directory}:ro ${simg} \bids-validator ${bids_directory}
```

## 1. Log into oscar and start an interactive section

If you are using the [Desktop app on Open OnDemand](https://docs.ccv.brown.edu/bnc-user-manual/xnat-to-bids-intro/bids-validation/pages/HF8lWyKP9liCNShWrkU7#id-1.-start-an-interactive-session), then you are already inside an interactive session and you just need to open the terminal. Otherwise, you can start an interactive job of 1 hour with

```bash
interact -n 2 -t 01:00:00 -m 8g
```

## 2. Define variables

### Specify the version of the validator you want to use.

```bash
version=v1.15.0
```

This is the last version of the validator before they switched to the new BIDS Schema Validator 2.0.

### Set up paths

Specify your **bids directory.** This is where `dataset_description.json` file lives

```bash
bids_directory=${HOME}/xnat-exports/bnc/study-demodat2/bids
```

Path to Singularity Image for the bids-validator (maintained by bnc)

```bash
simg=/oscar/data/bnc/simgs/bids/validator-${version}.sif
```

## 3. Run the main executable via singularity

The following command runs the `bids-validator` executable (via singularity) to test if a directory is BIDS compliant. The command tells singularity to launch the `validator-${version}.sif` image and execute the `bids-validator` command. The bids validator expects a directory as an input, which in this case corresponds to `${bids_directory}`. The `--bind ${bids_directory}:${bids_directory}:ro` makes the `${HOME}/xnat-exports/bnc/study-demodat/bids` available read-only inside the container at the same path.

```bash
singularity exec --bind ${bids_directory}:${bids_directory}:ro ${simg} \bids-validator ${bids_directory}
```