protobuf-c, a C implementation of the Google Protocol Buffers data serialization format. It includes
libprotobuf-c, a pure C library that implements protobuf encoding and decoding, and
protoc-c, a code generator that converts Protocol Buffer
.proto files to C descriptor code, based on the original
protobuf-c formerly included an RPC implementation; that code has been split out into the protobuf-c-rpc project.
protobuf-c was originally written by Dave Benson and maintained by him through version 0.15 but is now being maintained by a new team. Thanks, Dave!
protobuf-c requires a C compiler, a C++ compiler, protobuf, and
pkg-config to be installed.
./configure && make && make install
If building from a git checkout, the
libtool) must also be installed, and the build system must be generated by running the
./autogen.sh && ./configure && make && make install
protoc command to generate
.pb-c.h output files from your
.proto input file. The
--c_out options instructs
protoc to use the protobuf-c plugin.
protoc --c_out=. example.proto
.pb-c.h file from your C source code.
Compile your C source code together with the
.pb-c.c file. Add the output of the following command to your compile flags.
pkg-config --cflags 'libprotobuf-c >= 1.0.0'
Link against the
libprotobuf-c support library. Add the output of the following command to your link flags.
pkg-config --libs 'libprotobuf-c >= 1.0.0'
If using autotools, the
PKG_CHECK_MODULES macro can be used to detect the presence of
libprotobuf-c. Add the following line to your
PKG_CHECK_MODULES([PROTOBUF_C], [libprotobuf-c >= 1.0.0])
This will place compiler flags in the
PROTOBUF_C_CFLAGS variable and linker flags in the
PROTOBUF_C_LDFLAGS variable. Read more information here about the
protobuf-c follows the Semantic Versioning Specification as of version 1.0.0.
Note that as of version of 1.0.0, the header files generated by the
protoc-c compiler contain version guards to prevent incompatibilities due to version skew between the
.pb-c.h files generated by
protoc-c and the public
protobuf-c.h include file supplied by the
libprotobuf-c support library. While we will try not to make changes to
protobuf-c that will require triggering the version guard often, such as releasing a new major version of
protobuf-c, this cannot be guaranteed. Thus, it's a good idea to recompile your
.pb-c.h files from their source
.proto files with
protoc-c as part of your build system, with proper source file dependency tracking, rather than shipping potentially stale
.pb-c.h files that may not be compatible with the
libprotobuf-c headers installed on the system in project artifacts like repositories and release tarballs. (Note that the output of the
protoc-c code generator is not standalone, as the output of some other tools that generate C code is, such as
Major API/ABI changes may occur between major version releases, by definition. It is not recommended to export the symbols in the code generated by
protoc-c in a stable library interface, as this will embed the
protobuf-c ABI into your library's ABI. Nor is it recommended to install generated
.pb-c.h files into a public header file include path as part of a library API, as this will tie clients of your library's API to particular versions of
Please send patches to the protobuf-c mailing list or by opening a GitHub pull request.
The most recently released
protobuf-c version is kept on the
master branch, while the
next branch is used for commits targeted at the next release. Please base patches and pull requests against the
next branch, not the
Copyright to all contributions are retained by the original author, but must be licensed under the terms of the BSD-2-Clause license. Please add a
Signed-off-by header to your commit message (
git commit -s) to indicate that you are licensing your contribution under these terms.