add cmd check

.hooks/pre-commit

@@ -14,6 +14,7 @@ changed_files=$(git diff-index --cached $against | \
 	grep -E '[MA]	.*\.(c|cpp|cc|cxx)$' | cut -d'	' -f 2)
 
 
+if which cppcheck > /dev/null; then 
 	if [ -n "$changed_files" ]; then
 		cppcheck --enable=warning,performance,portability --inline-suppr --error-exitcode=1 --platform=win64 --force $changed_files
 		err=$?
@@ -24,13 +25,16 @@ if [ -n "$changed_files" ]; then
 			echo "[rt-thread][cppcheck] cppcheck ok."
 		fi
 	fi
+else
+    echo "cppcheck does not exist" 
+fi
 
 # We only filter the file name with c or cpp or h file.
 # astyle only astyle the added file[because of code reivewer], if you want change modify file, please use [MA]
 changed_files=$(git diff-index --cached $against | \
 	grep -E '[MA]	.*\.(c|cpp|h)$' | cut -d'	' -f 2)
 
-
+if which astyle > /dev/null; then 
 	if [ -n "$changed_files" ]; then
 		astyle --style=allman --indent=spaces=4 --indent=spaces=4 --indent=spaces=4 --pad-header --pad-header --pad-header --align-pointer=name --lineend=linux --convert-tabs --verbose  $changed_files
 		err=$?
@@ -41,7 +45,9 @@ if [ -n "$changed_files" ]; then
 			echo "[rt-thread][astyle] astyle file ok"
 		fi
 	fi
-
+else
+    echo "astyle does not exist" 
+fi
 
 # We only filter the file name with c or cpp file.
 changed_files=$(git diff-index --cached $against | \
@@ -49,11 +55,16 @@ changed_files=$(git diff-index --cached $against | \
 # formatting check
 # https://github.com/mysterywolf/formatting
 # formatting cmd ref https://github.com/supperthomas/git_auto_script
+if which formatting > /dev/null; then 
 	if [ -n "$changed_files" ]; then
 		formatting $changed_files
 		echo "[rt-thread] formatting $changed_files is ok"
 		git add $changed_files
 		exit 0
 	fi
+else
+    echo "formatting does not exist" 
+fi
+
 exit 0