Improved build script for tensorflow example, fixed readme (#553)

samples/tensorflow/README.md

@@ -8,16 +8,14 @@ this example is built on top of the
 [TensorFlow C API](https://github.com/tensorflow/tensorflow/blob/r1.1/tensorflow/c/c_api.h), 
 showing how a TensorFlow client in Kotlin/Native could look like.
 
-##Installation
-
-[Install TensorFlow for C](https://www.tensorflow.org/versions/r1.1/install/install_c) into `/usr/local`.
-
-Compile:
+## Installation
 
     ./build.sh
 
-Run:
+will install [TensorFlow for C](https://www.tensorflow.org/versions/r1.1/install/install_c) into `/opt/local` (if not yet done) and build the example.
 
     ./HelloTensorflow.kexe
 
-You may need to specify `LD_LIBRARY_PATH` or `DYLD_LIBRARY_PATH` to `/opt/local/lib` if TensorFlow dynamic library cannot be found.
+will then run the example.
+
+You may need to specify `LD_LIBRARY_PATH` or `DYLD_LIBRARY_PATH` to `/opt/local/lib` if the TensorFlow dynamic library cannot be found.

samples/tensorflow/build.sh

@@ -2,7 +2,8 @@
 
 PATH=../../dist/bin:../../bin:$PATH
 DIR=.
-TF_TARGET_DIRECTORY="/opt/local"
+TF_TARGET_DIRECTORY="/opt/local" # If you change this, adapt compilerOpts in tensorflow.def accordingly
+TF_TYPE="cpu" # Change to "gpu" for GPU support
 
 if [ x$TARGET == x ]; then
 case "$OSTYPE" in
@@ -20,9 +21,8 @@ var=COMPILER_ARGS_${TARGET}
 COMPILER_ARGS=${!var} # add -opt for an optimized build.
 
 if [ ! -d $TF_TARGET_DIRECTORY/include/tensorflow ]; then
- echo "Installing TensorFlow..."
- TF_TYPE="cpu" # Change to "gpu" for GPU support
- TF_TARGET_DIRECTORY="/opt/local"
+ echo "Installing TensorFlow into $TF_TARGET_DIRECTORY ..."
+ sudo mkdir -p $TF_TARGET_DIRECTORY
  curl -s -L \
    "https://storage.googleapis.com/tensorflow/libtensorflow/libtensorflow-${TF_TYPE}-${TF_TARGET}-x86_64-1.1.0.tar.gz" |
    sudo tar -C $TF_TARGET_DIRECTORY -xz
@@ -30,4 +30,4 @@ fi
 
 cinterop -def $DIR/tensorflow.def -copt "$CFLAGS" -target $TARGET -o tensorflow.kt.bc || exit 1
 konanc $COMPILER_ARGS -target $TARGET $DIR/HelloTensorflow.kt -library tensorflow.kt.bc -o HelloTensorflow.kexe \
-    -linkerArgs "-L/opt/local/lib -ltensorflow" || exit 1
+    -linkerArgs "-L$TF_TARGET_DIRECTORY/lib -ltensorflow" || exit 1