pre-commit currently passes selected filenames to hooks via argv.
For large changesets (or --all-files), argv length limits are hit and
filenames are partitioned, causing multiple hook invocations.
This means there is currently no built-in way to pass filenames to an
underlying hook in one shot without chunking / re-running. The only practical
workaround is to set pass_filenames: false and run custom git operations in
hook code to reconstruct the file set, which is expensive and duplicates
pre-commit's own file-selection logic.
This change adds a hook option:
pass_filenames_via_stdin: true
When enabled, pre-commit sends filenames as NUL-delimited bytes on stdin and
runs the hook in a single invocation (no argv chunking).
Why NUL-delimited stdin:
- safe for filenames containing spaces/newlines
- matches established -0 conventions in unix tooling
Usage for hook authors:
- shell:
while IFS= read -r -d '' filename; do
...
done
- python:
data = sys.stdin.buffer.read()
filenames = [os.fsdecode(p) for p in data.split(b'\0') if p]
Behavior notes:
- default remains argv-based passing
- pass_filenames: false still disables filename passing entirely
Implementation includes schema/runtime wiring, shared NUL encode/decode
helpers, and tests covering defaulting and runtime behavior.
This patch adds 2nd class support for hooks using julia as the language.
pre-commit will install any dependencies defined in the hooks repo
`Project.toml` file, with support for `additional_dependencies` as well.
Julia doesn't (yet) have a way to install binaries/scripts so for julia
hooks the `entry` value is a (relative) path to a julia script within
the hooks repository. When executing a julia hook the (globally
installed) julia interpreter is prepended to the entry.
Example `.pre-commit-hooks.yaml`:
```yaml
- id: foo
name: ...
language: julia
entry: bin/foo.jl --arg1
```
Example hooks repo: https://github.com/fredrikekre/runic-pre-commit/tree/fe/julia
Accompanying pre-commit.com PR: https://github.com/pre-commit/pre-commit.com/pull/998Fixes#2689.
