|  | This directory contains the useful tools. | 
|  |  | 
|  |  | 
|  | ## build_android.sh | 
|  | This script is to build PyTorch/Caffe2 library for Android. Take the following steps to start the build: | 
|  |  | 
|  | - set ANDROID_NDK to the location of ndk | 
|  |  | 
|  | ```bash | 
|  | export ANDROID_NDK=YOUR_NDK_PATH | 
|  | ``` | 
|  |  | 
|  | - run build_android.sh | 
|  | ```bash | 
|  | #in your PyTorch root directory | 
|  | bash scripts/build_android.sh | 
|  | ``` | 
|  | If succeeded, the libraries and headers would be generated to build_android/install directory. You can then copy these files from build_android/install to your Android project for further usage. | 
|  |  | 
|  | You can also override the cmake flags via command line, e.g., following command will also compile the executable binary files: | 
|  | ```bash | 
|  | bash scripts/build_android.sh -DBUILD_BINARY=ON | 
|  | ``` | 
|  |  | 
|  | ## build_ios.sh | 
|  | This script is to build PyTorch/Caffe2 library for iOS, and can only be performed on macOS. Take the following steps to start the build: | 
|  |  | 
|  | - Install Xcode from App Store, and configure "Command Line Tools" properly on Xcode. | 
|  | - Install the dependencies: | 
|  |  | 
|  | ```bash | 
|  | brew install cmake automake libtool | 
|  | ``` | 
|  |  | 
|  | - run build_ios.sh | 
|  | ```bash | 
|  | #in your PyTorch root directory | 
|  | bash scripts/build_ios.sh | 
|  | ``` | 
|  | If succeeded, the libraries and headers would be generated to build_ios/install directory. You can then copy these files  to your Xcode project for further usage. |