PowerShell实现统计函数嵌套深度
当你调用某个函数时,PowerShell会增加一次嵌套层次。当一个函数调用了另一个函数,或着脚本,也会增加嵌套层次。今天分享一个函数,它能告诉你的脚本嵌套的层次:
functionTest-NestLevel { $i=1 $ok=$true do { try { $test=Get-Variable-NameHost-Scope$i } catch { $ok=$false } $i++ }While($ok) $i }
当你调用的函数具有递归调用时,上面的函数非常有用,来看一个调用的示例:
functionTest-Diving { param($Depth) if($Depth-gt10){return} "Divingdeeperto$Depthmeters..." $currentDepth=Test-NestLevel "calculateddepth:$currentDepth" Test-Diving-depth($Depth+1) } Test-Diving-depth1
当你运行Test-Diving时,函数会调用自己10次。函数使用一个参数来控制嵌套层次,而Test-NestLevel负责返回确切的深度数。
注意这里有个区别:Test-NestLevel返回绝对的嵌套层次,参数会纪录这个函数调用自己多少次。如果Test-Diving被嵌入到另外一个函数中,绝对深度和相对深度会不同。
PSC:\>Test-Diving-Depth1 divingdeeperto1meters... calculateddepth:1 divingdeeperto2meters... calculateddepth:2 divingdeeperto3meters... calculateddepth:3 divingdeeperto4meters... calculateddepth:4 divingdeeperto5meters... calculateddepth:5 divingdeeperto6meters... calculateddepth:6 divingdeeperto7meters... calculateddepth:7 divingdeeperto8meters... calculateddepth:8 divingdeeperto9meters... calculateddepth:9 divingdeeperto10meters... calculateddepth:10 PSC:\>&{Test-Diving-Depth1} divingdeeperto1meters... calculateddepth:2 divingdeeperto2meters... calculateddepth:3 divingdeeperto3meters... calculateddepth:4 divingdeeperto4meters... calculateddepth:5 divingdeeperto5meters... calculateddepth:6 divingdeeperto6meters... calculateddepth:7 divingdeeperto7meters... calculateddepth:8 divingdeeperto8meters... calculateddepth:9 divingdeeperto9meters... calculateddepth:10 divingdeeperto10meters... calculateddepth:11 PSC:\>
Test-NestLevel总会返回从当前代码的作用域到全局作用域的嵌套深度。