changed build fail behavior, added clean checks

cbuild.sh

@@ -117,22 +117,29 @@ build() {
     export_vars
     make -f "${MAKEFILE}" -e "${TARGET}" -n | grep "^${CC}" | wc -l > .cbuild_prog.tmp
     info "Beginning build..."
-    make -f "${MAKEFILE}" -e "${TARGET}" &&
+    make -f "${MAKEFILE}" -e "${TARGET}"
+    ret=$?
+    [ "${ret}" = 0 ] &&
         info "Build SUCCESSFUL" ||
         err "Build FAILURE"
     rm .cbuild_prog.tmp
+    return "${ret}"
 }
 
 clean() {
+    [ -d "${OBJDIR}" ] &&
         rm -rf "${OBJDIR}"
+    [ -f "${MAKEFILE}" ] &&
         chmod +w "${MAKEFILE}"
+    [ -f "${TARGET}" ] && [ -f "${MAKEFILE}" ] &&
         rm "${TARGET}" "${MAKEFILE}"
 }
 
 run() {
-    build
+    build || exit $?
 	info "Running ./${TARGET}"
-    "./${TARGET}"
+    "./${TARGET}" ||
+        err "Run FAILURE ./${TARGET} returned $?"
 }
 
 dry_run() {