decode_raw

A protobuf debugging tool – protoc --decode_raw on steroids.

Highlights

Beautiful output

Small and large data supported well

Large binary data is truncated by default. The length is always visible. You can use --full to show the full data. In combination with the message selection (see below) you can get an overview first and then get the full data of specific fields.

Nicely escaped JSON content

String content is ready to be pasted to things like echo '{"my": "json"}' | jq.

Select submessages

Use a jq-like syntax to select sub-messages only.

Advanced type detection

The tool decides between nested protobuf messages, strings and raw bytes on a best-guess basis. Sometimes it is wrong but you can help. E.g. if you know, no fixed length types are used, add --no-fixed to get the correct output.

Installation

Install from crates.io:

sh cargo install decode_raw

Update to latest version:

sh cargo install --force decode_raw

Basic usage

decode_raw reads serialized protobuf from STDIN and prints it.

From pipe

$ echo 08bf99bfb4e502120a4a616e6520536d697468 | xxd -r -p | decode_raw 1: 95941545151 2: (10 bytes) 'Jane Smith'

From file

decode_raw < docs/person.bin 1: 1021211 2: (8 bytes) 'John Doe' 3 { · 1: 959435311 · 2: (11 bytes) 'Susanne Doe' } 3 { · 1: 81154811 · 2: (9 bytes) 'Mac Smith' · 3 { · · 1: 95941545151 · · 2: (10 bytes) 'Jane Smith' · } }

Goals & non-goals

decode_raw should

• Make Simon happy when debugging protobuf
• Be trivial to get started for users of protoc --decode_raw
• Support proto3

but it does not intend to:

• Provide stable outputs for scripting
• Become a performance winner
• Help with broken protobuf serialization. Those will be considered raw app level bytes.
• Support proto2

License

Apache 2.0, see LICENSE and NOTICE.