Is there a definitive *nix command line tool for inspecting protocol buffers? [closed]

Question

I'm looking for a command-line utility that will, at a minimum, render binary protobuf data in human-readable form. Filtering and selection options (along the lines of cut for text) would be nice, but the primary object is to make the data visible for debugging purposes.

If there is no definitive tool for the job, links to relevant packages are fine.

Answer 1

The Protocol Compiler -- protoc -- has this functionality built-in via the --decode and --decode_raw flags. This is the same tool you use to generate code from a .proto file so is likely already installed.

For example:

protoc --decode_raw < message.bin 

Or using the .proto file:

protoc --decode mypkg.MyType myschema.proto < message.bin 

Here is the --help text:

Usage: protoc [OPTION] PROTO_FILES Parse PROTO_FILES and generate output based on the options given:   -IPATH, --proto_path=PATH   Specify the directory in which to search for                               imports.  May be specified multiple times;                               directories will be searched in order.  If not                               given, the current working directory is used.   --version                   Show version info and exit.   -h, --help                  Show this text and exit.   --encode=MESSAGE_TYPE       Read a text-format message of the given type                               from standard input and write it in binary                               to standard output.  The message type must                               be defined in PROTO_FILES or their imports.   --decode=MESSAGE_TYPE       Read a binary message of the given type from                               standard input and write it in text format                               to standard output.  The message type must                               be defined in PROTO_FILES or their imports.   --decode_raw                Read an arbitrary protocol message from                               standard input and write the raw tag/value                               pairs in text format to standard output.  No                               PROTO_FILES should be given when using this                               flag.   -oFILE,                     Writes a FileDescriptorSet (a protocol buffer,     --descriptor_set_out=FILE defined in descriptor.proto) containing all of                               the input files to FILE.   --include_imports           When using --descriptor_set_out, also include                               all dependencies of the input files in the                               set, so that the set is self-contained.   --include_source_info       When using --descriptor_set_out, do not strip                               SourceCodeInfo from the FileDescriptorProto.                               This results in vastly larger descriptors that                               include information about the original                               location of each decl in the source file as                               well as surrounding comments.   --error_format=FORMAT       Set the format in which to print errors.                               FORMAT may be 'gcc' (the default) or 'msvs'                               (Microsoft Visual Studio format).   --print_free_field_numbers  Print the free field numbers of the messages                               defined in the given proto files. Groups share                               the same field number space with the parent                                message. Extension ranges are counted as                                occupied fields numbers.   --plugin=EXECUTABLE         Specifies a plugin executable to use.                               Normally, protoc searches the PATH for                               plugins, but you may specify additional                               executables not in the path using this flag.                               Additionally, EXECUTABLE may be of the form                               NAME=PATH, in which case the given plugin name                               is mapped to the given executable even if                               the executable's own name differs.   --cpp_out=OUT_DIR           Generate C++ header and source.   --java_out=OUT_DIR          Generate Java source file.   --python_out=OUT_DIR        Generate Python source file.