# CLI options

pperl accepts a small set of command-line flags. Most are `perl`-compatible;
a handful are pperl-specific (JIT, parallelism, runtime selection, bytecode
cache). The authoritative list is whatever `pperl --help` prints; the tables
below show those flags, extracted from the interpreter source and rendered
here on every documentation build.

:::{note}
The actual `pperl --help` output on the terminal is always in English —
the binary does not localise help strings. Translated documentation
shows the same flags with descriptions in the page's language so
readers can study what each flag does; flag tokens (`-T`, `--pp`,
`--threads=N`, …) are always verbatim.
:::

```{include} ../_generated/pperl-help-table.md
```

## Environment variables

pperl sets several environment variables inside the process it runs, so
scripts can introspect the running interpreter:

| Variable           | Meaning                                                      |
|--------------------|--------------------------------------------------------------|
| `PPERL`            | Version string (same as `pperl -v`)                          |
| `PPERL_FEATURES`   | Comma-separated list of compiled-in Cargo features           |
| `PPERL_MODS`       | Comma-separated `Name/version` pairs for every native module |
| `PPERL_RUNTIMES`   | Comma-separated runtimes built in (`p5`, `pp`, or both)      |
| `PPERL_SHELL`      | Shell integration flavor (empty if `shell` feature off)      |
| `PPERL_STATIC`     | `yes` if the binary is musl-statically linked, else `no`     |

Run `pperl -V` to see all values for the current binary.

## When to use `--pp`

The default **p5 runtime** is the full-feature interpreter: every module
available, JIT enabled, taint mode functional. `--pp` selects the
native-Rust **pp runtime** — faster to start, smaller binary, but with
a narrower module set and no JIT. Pick `--pp` for miniperl-style
deployments or when the specific module you need is available in it
(see the `pp` runtime badge on module pages).