该变量BUILDNUMBER设置为值 230。我希望230_为命令打印，echo $BUILDNUMBER_但输出为空，如下所示。
BUILDNUMBER
230_
echo $BUILDNUMBER_
# echo $BUILDNUMBER_ # echo $BUILDNUMBER 230
bash shell-script variable-substitution
bash ×1
shell-script ×1
variable-substitution ×1