diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..0ee6085
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/udp2raw*
diff --git a/makefile b/makefile
index 2ffea6b..fcdbf2d 100755
--- a/makefile
+++ b/makefile
@@ -1,13 +1,13 @@
 cc_cross=/home/wangyu/Desktop/arm-2014.05/bin/arm-none-linux-gnueabi-g++
 cc_local=g++
-cc_mips24kc_be=/toolchains/lede-sdk-17.01.2-ar71xx-generic_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-mips_24kc_gcc-5.4.0_musl-1.1.16/bin/mips-openwrt-linux-musl-g++
-cc_mips24kc_le=/toolchains/lede-sdk-17.01.2-ramips-mt7621_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-mipsel_24kc_gcc-5.4.0_musl-1.1.16/bin/mipsel-openwrt-linux-musl-g++
-cc_arm= /toolchains/lede-sdk-17.01.2-bcm53xx_gcc-5.4.0_musl-1.1.16_eabi.Linux-x86_64/staging_dir/toolchain-arm_cortex-a9_gcc-5.4.0_musl-1.1.16_eabi/bin/arm-openwrt-linux-c++
+cc_mips24kc_be=$(shell which g++ || /toolchains/lede-sdk-17.01.2-ar71xx-generic_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-mips_24kc_gcc-5.4.0_musl-1.1.16/bin/mips-openwrt-linux-musl-g++)
+cc_mips24kc_le=$(shell which g++ || /toolchains/lede-sdk-17.01.2-ramips-mt7621_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-mipsel_24kc_gcc-5.4.0_musl-1.1.16/bin/mipsel-openwrt-linux-musl-g++)
+cc_arm= $(shell which c++ || /toolchains/lede-sdk-17.01.2-bcm53xx_gcc-5.4.0_musl-1.1.16_eabi.Linux-x86_64/staging_dir/toolchain-arm_cortex-a9_gcc-5.4.0_musl-1.1.16_eabi/bin/arm-openwrt-linux-c++)
 cc_mingw_cross=i686-w64-mingw32-g++-posix
 cc_mac_cross=o64-clang++ -stdlib=libc++
-cc_x86=/toolchains/lede-sdk-17.01.2-x86-generic_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-i386_pentium4_gcc-5.4.0_musl-1.1.16/bin/i486-openwrt-linux-c++
-cc_amd64=/toolchains/lede-sdk-17.01.2-x86-64_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-x86_64_gcc-5.4.0_musl-1.1.16/bin/x86_64-openwrt-linux-c++
-#cc_bcm2708=/home/wangyu/raspberry/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++ 
+cc_x86=$(shell which c++ || /toolchains/lede-sdk-17.01.2-x86-generic_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-i386_pentium4_gcc-5.4.0_musl-1.1.16/bin/i486-openwrt-linux-c++)
+cc_amd64=$(shell which c++ || /toolchains/lede-sdk-17.01.2-x86-64_gcc-5.4.0_musl-1.1.16.Linux-x86_64/staging_dir/toolchain-x86_64_gcc-5.4.0_musl-1.1.16/bin/x86_64-openwrt-linux-c++)
+#cc_bcm2708=$(shell which g++ || /home/wangyu/raspberry/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++)
 
 
 FLAGS= -std=c++11   -Wall -Wextra -Wno-unused-variable -Wno-unused-parameter -Wno-missing-field-initializers ${OPT}