Merge pull request #1087 from sofia-riese/patch-2

Corrects potential errors when filenames are separated by spaces

scripts/libs/check_dir_avail.sh

@@ -1,5 +1,5 @@
 #检查目录剩余空间——$1:目标路径 $2:-h参数
 dir_avail() {
 	df -h >/dev/null 2>&1 && h="$2"
-    df -P $h "${1:-.}" 2>/dev/null | awk 'NR==2 {print $(NF-2)}'
-}
+    df -P $h "${1:-.}" 2>/dev/null | awk 'NR==2 {print $4}'
+}