From the
tree(1)
release notes,
version 2.0.0:
- Output un-indented JSON on file descriptor 3 ("stddata") automatically if file descriptor 3 is present (currently Linux only.) Maybe switch to BSON.
Surely, nothing will happen if I just assume that the existence of a specific file descriptor implies something, as nobody is crazy or stupid enough to hardcode such a thing? <insert sounds of cars crashing in the background>
Oops (from the tree
version 2.0.2 release notes):
- Okay, apparently the stddata addition is causing havoc (who knew how many scripts just haphazardly hand programs random file descriptors, that's surely not a problem.) Going forward the stddata option will only work if the environment variable STDDATA_FD is present or set to the descriptor to produce the JSON output on.
Assuming anything about the users environment is and will always be a mistake.
But it's still cool we can have tree
output structured data using
STDDATA_FD
:
> STDDATA_FD=1 tree
[{"type":"directory","name":".","contents":[{"type":"file","name":"2024-01-01-test.md"},{"type":"file","name":"2024-03-04-htmnix.md"},{"type":"file","name":"2024-04-02-cosmic-drift.md"},{"type":"file","name":"2024-04-15-nix-iceberg.md"},{"type":"file","name":"2024-05-20-swap-i.md"},{"type":"file","name":"2024-09-30-gitignore.md"},{"type":"file","name":"2025-06-05-why-cores.md"},{"type":"file","name":"2025-06-09-nginix.md"},{"type":"file","name":"2025-06-20-intro-cab.md"},{"type":"file","name":"2025-07-04-derive-broken.md"},{"type":"file","name":"2025-07-20-no-gnulib.md"},{"type":"file","name":"_data.ts"}]},{"type":"report","directories":1,"files":12}]
Also, obligatory nushell mention (using the markdown
table style because for some reason the fancy characters don't render properly
with my webfont):
> STDDATA_FD=1 tree | from json
|-#-|---type----|-name-|------------------contents-------------------|-directories-|-files-|
| 0 | directory | . | |-#--|-type-|------------name-------------| | nope | nope |
| | | | | 0 | file | 2024-01-01-test.md | | | |
| | | | | 1 | file | 2024-03-04-htmnix.md | | | |
| | | | | 2 | file | 2024-04-02-cosmic-drift.md | | | |
| | | | | 3 | file | 2024-04-15-nix-iceberg.md | | | |
| | | | | 4 | file | 2024-05-20-swap-i.md | | | |
| | | | | 5 | file | 2024-09-30-gitignore.md | | | |
| | | | | 6 | file | 2025-06-05-why-cores.md | | | |
| | | | | 7 | file | 2025-06-09-nginix.md | | | |
| | | | | 8 | file | 2025-06-20-intro-cab.md | | | |
| | | | | 9 | file | 2025-07-04-derive-broken.md | | | |
| | | | | 10 | file | 2025-07-20-no-gnulib.md | | | |
| | | | | 11 | file | _data.ts | | | |
| 1 | report | nope | nope | 1 | 12 |