headson

Budget‑constrained JSON preview for the terminal.

Install

Using Cargo:

cargo install headson

From source:

cargo build --release
target/release/headson --help

headson [FLAGS] [INPUT...]

INPUT (optional, repeatable): file path(s). If omitted, reads JSON from stdin. Multiple input files are supported.
Prints the preview to stdout. On parse errors, exits non‑zero and prints an error to stderr.

Common flags:

-n, --budget <BYTES>: output byte budget (default: 500). When multiple input files are provided, the total budget equals <BYTES> * number_of_inputs (budget is per input).
-f, --template <json|pseudo|js>: output style (default: pseudo)
-m, --compact: no indentation, no spaces, no newlines
--no-newline: single line output
--no-space: no space after : in objects
--indent <STR>: indentation unit (default: two spaces)
--string-cap <N>: max graphemes to consider per string (default: 500)

Notes:

With multiple input files:
- JSON template outputs a single JSON object keyed by the input file paths.
- Pseudo and JS templates render file sections with human-readable headers.

Examples:

Read from stdin with defaults:
```
cat data.json | headson
```
Read from file, JS style, 200‑byte budget:
```
headson -n 200 -f js data.json
```
JSON style, compact:
```
headson -f json -m data.json
```
Multiple files (JSON template produces an object keyed by paths):
```
headson -f json a.json b.json
```

Show help:

headson --help