Your company here — click to reach over 10,000 unique daily visitors

protoc - Man Page

Protobuf compiler

Examples (TL;DR)




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. If not found in any of the these directories, the --descriptor_set_in descriptors will be checked for required proto file.


Show version info and exit.

-h,  --help

Show a help message and exit.


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.


When using --encode, ensure map fields are deterministically ordered. Note that this order is not canonical, and changes across builds or releases of protoc(1).


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.


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.


Specifies a delimited list of FILES each containing a FileDescriptorSet (a protocol buffer defined in descriptor.proto). The FileDescriptor for each of the PROTO_FILES provided will be loaded from these FileDescriptorSets. If a FileDescriptor appears multiple times, the first occurrence will be used.

-oFILE,  --descriptor_set_out=FILE

Writes a FileDescriptorSet (a protocol buffer, defined in descriptor.proto) containing all of the input files to FILE.


When using --descriptor_set_out, also include all dependencies of the input files in the set, so that the set is self-contained.


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.


Write a dependency output file in the format expected by make(1). This writes the transitive set of input file paths to FILE


Set the format in which to print errors. FORMAT may be ‘gcc’ (the default) or (Microsoft Visual Studio format).


Make warnings be fatal (similar to -Werr in gcc(1)). This flag will make protoc(1)
return with a non-zero exit code if any warnings are generated.


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.


Specifies a plugin executable to use. Normally, protoc(1) 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.


Generate C++ header and source.


Generate C# source file.


Generate Java source file.


Generate JavaScript source.


Generate Kotlin file.


Generate Objective-C header and source.


Generate PHP source file.


Generate Python source file.


Generate Ruby source file.


Read options and filenames from file. If a relative file path is specified, the file will be searched in the working directory. The --proto_path option will not affect how this argument file is searched. Content of the file will be expanded in the position of @<filename> as in the argument list. Note that shell expansion is not applied to the content of the file (i.e., you cannot use quotes, wildcards, escapes, commands, etc.). Each line corresponds to a single argument, even if it contains spaces.

See Also

make(1), gcc(1)


December 2022