$FUNCNAME: Function Call Stack
$FUNCNAME contains the names of shell functions on the execution call stack.
The name of the currently executed function is ${FUNCNAME[0]}, the name of the calling function is ${FUNCNAME[1]}
and so on. The element with the highest index has value main.
Links
BashSupport Pro 是一个 支持 $FUNCNAME 的 Bash 集成开发工具 – 马上试用！