在Android.mk编译脚本中使用shell bash命令

在Android的编译脚本中有很多示例，比如在 build/core/main.mk 文件中：ifeq （$（BUILD_OS）,linux）build_arch := $（shell uname -m）ifneq （64,$（findstring 64,$（build_arch）））$（warning ************************************************************）$（warning You are attempting to build on a 32-bit system.）$（warning Only 64-bit build environments are supported beyond froyo/2.2.）$（warning ************************************************************）$（error stop）endifendif
ifneq （$（HOST_OS）,windows）ifneq （$（HOST_OS）-$（HOST_ARCH）,darwin-ppc）# check for a case sensitive file systemifneq （a,$（shell mkdir -p $（OUT_DIR） ; echo a > $（OUT_DIR）/casecheck.txt; echo B > $（OUT_DIR）/CaseCheck.txt; cat $（OUT_DIR）/casecheck.txt））$（warning ************************************************************）$（warning You are building on a case-insensitive filesystem.）$（warning Please move your source tree to a case-sensitive filesystem.）$（warning ************************************************************）$（error Case-insensitive filesystems not supported）endifendifendif