---
title: The file format
description: What a line of the env file may hold, and why a dollar sign is never expanded.
order: 3
---

Ops writes one `NAME=value` per line. A value is written bare unless it holds `$`, `\`,
`"`, `'`, `#` or whitespace; then it is double quoted, with `\\`, `\"`, `\$` and `\n` as
escapes. ops-env reads that back byte for byte, exactly as the Rust SDK does.

```text
LOG_FORMAT=json
DATABASE_URL=postgres://web:p4ss@db:5432/rungholt
SIGNING_KEY="a\$b\\c"
```

## A dollar sign is never expanded

Node's `--env-file`, Bun's own `.env` loading and dotenv-expand replace `$NAME` inside a
value, and not all of them honour `\$`. A generated password holding `$abc` then becomes a
different password. ops-env never expands anything: a bare value is taken as written,
backslashes included. This is the reason to use it instead of `--env-file`.

## Hand written files

For the `.env` you write yourself it also reads:

- blank lines and lines starting with `#`;
- an `export ` prefix;
- single quoted values, taken literally;
- a ` # comment` after a value;
- Windows line ends;
- double quoted values that span lines;
- `\'` and a backslash before a space inside double quotes.