# base-libfuzzer > Abstract base image for libfuzzer builders. `docker run -ti ` # Supported Commands | Command | Description | |---------|-------------| | `compile` (default) | build all fuzzers | `reproduce ` | build all fuzzers and run specified one with `/testcase` content. | `run ` | build all fuzzers and run specified one with given options. | `test` | build all fuzzers and run each one for a little while to verify it is working correctly. | `/bin/bash` | drop into shell, execute `compile` script to start build. # Image Files Layout | Location | Description | | -------- | ---------- | | `/out/` (`$OUT`) | build artifacts should be copied here | | `/src/` (`$SRC`) | place to checkout source files | | `/work/`(`$WORK`) | used to store intermediate files | | `/usr/lib/libfuzzer.a` | libfuzzer static library | While files layout is fixed within a container, `$SRC`, `$OUT`, `$WORK` are provided to be able to write retargetable scripts. ## Compiler Flags You *must* use special compiler flags to build your target and fuzzers. These flags are provided in following environment variables: | Env Variable | Description | ------------- | -------- | `$CC` | The C compiler binary. | `$CXX`, `$CCC` | The C++ compiler binary. | `$CFLAGS` | C compiler flags. | `$CXXFLAGS` | C++ compiler flags. Many well-crafted build scripts will automatically use these variables. If not, passing them manually to a build tool might be required. # Child Image Interface ## Sources Child image has to checkout all sources it needs to compile fuzzers into `$SRC` directory. When the image is executed, a directory could be mounted on top of these with local checkouts using `docker run -v $HOME/my_target:/src/my_target ...`. ## Other Required Files Following files have to be added by child images: | File Location | Description | | ------------- | ----------- | | `$SRC/build.sh` | build script to build the target and its fuzzers |