PowerShellでeval


アニメ「Classroom☆Crisis」(2015)

生徒に、妹もいれば、上司もいるクラスです。
勉強しながら夢を追いかけてばかりいる部署なので、会社からはお荷物の様子。生徒として転入してきたやり手の上司は、この部署を潰そうとしています。
評価した結果、必要ないものなら捨てるのは当然かもしれませんが、夢まで捨てる必要はないと思います。

Perlでeval(評価)を使うと、ワンライナーが楽に書けます。
1~5までのsum。

takk@deb9:~$ perl -E 'say eval join"+",1..5'
15
takk@deb9:~$

PowerShell。計算式を作るには、join。

PS C:\Users\takk> 1..5 -join "+"
1+2+3+4+5
PS C:\Users\takk>

PowerShellでevalをやるには、ちょっと難しいコマンドを使います。Invoke-Expressionを使います。

PS C:\Users\takk> 1..5 -join "+" | invoke-expression
15
PS C:\Users\takk> 

Invoke-Expressionが、 とても覚えられません。なので、get-aliasだけ覚えておき、時々参照するようにしています。

PS C:\Users\takk> get-alias

CommandType     Name                                               ModuleName
-----------     ----                                               ----------
Alias           % -> ForEach-Object
Alias           ? -> Where-Object
Alias           ac -> Add-Content
Alias           asnp -> Add-PSSnapin
Alias           cat -> Get-Content
Alias           cd -> Set-Location
Alias           chdir -> Set-Location
Alias           clc -> Clear-Content
Alias           clear -> Clear-Host
Alias           clhy -> Clear-History
Alias           cli -> Clear-Item
Alias           clp -> Clear-ItemProperty
Alias           cls -> Clear-Host
Alias           clv -> Clear-Variable
Alias           cnsn -> Connect-PSSession
Alias           compare -> Compare-Object
Alias           copy -> Copy-Item
Alias           cp -> Copy-Item
Alias           cpi -> Copy-Item
Alias           cpp -> Copy-ItemProperty
Alias           curl -> Invoke-WebRequest
Alias           cvpa -> Convert-Path
Alias           dbp -> Disable-PSBreakpoint
Alias           del -> Remove-Item
Alias           diff -> Compare-Object
Alias           dir -> Get-ChildItem
Alias           dnsn -> Disconnect-PSSession
Alias           ebp -> Enable-PSBreakpoint
Alias           echo -> Write-Output
Alias           epal -> Export-Alias
Alias           epcsv -> Export-Csv
Alias           epsn -> Export-PSSession
Alias           erase -> Remove-Item
Alias           etsn -> Enter-PSSession
Alias           exsn -> Exit-PSSession
Alias           fc -> Format-Custom
Alias           fl -> Format-List
Alias           foreach -> ForEach-Object
Alias           ft -> Format-Table
Alias           fw -> Format-Wide
Alias           gal -> Get-Alias
Alias           gbp -> Get-PSBreakpoint
Alias           gc -> Get-Content
Alias           gci -> Get-ChildItem
Alias           gcm -> Get-Command
Alias           gcs -> Get-PSCallStack
Alias           gdr -> Get-PSDrive
Alias           ghy -> Get-History
Alias           gi -> Get-Item
Alias           gjb -> Get-Job
Alias           gl -> Get-Location
Alias           gm -> Get-Member
Alias           gmo -> Get-Module
Alias           gp -> Get-ItemProperty
Alias           gps -> Get-Process
Alias           group -> Group-Object
Alias           gsn -> Get-PSSession
Alias           gsnp -> Get-PSSnapin
Alias           gsv -> Get-Service
Alias           gu -> Get-Unique
Alias           gv -> Get-Variable
Alias           gwmi -> Get-WmiObject
Alias           h -> Get-History
Alias           history -> Get-History
Alias           icm -> Invoke-Command
Alias           iex -> Invoke-Expression
Alias           ihy -> Invoke-History
Alias           ii -> Invoke-Item
Alias           ipal -> Import-Alias
Alias           ipcsv -> Import-Csv
Alias           ipmo -> Import-Module
Alias           ipsn -> Import-PSSession
Alias           irm -> Invoke-RestMethod
Alias           ise -> powershell_ise.exe
Alias           iwmi -> Invoke-WMIMethod
Alias           iwr -> Invoke-WebRequest
Alias           kill -> Stop-Process
Alias           lp -> Out-Printer
Alias           ls -> Get-ChildItem
Alias           man -> help
Alias           md -> mkdir
Alias           measure -> Measure-Object
Alias           mi -> Move-Item
Alias           mount -> New-PSDrive
Alias           move -> Move-Item
Alias           mp -> Move-ItemProperty
Alias           mv -> Move-Item
Alias           nal -> New-Alias
Alias           ndr -> New-PSDrive
Alias           ni -> New-Item
Alias           nmo -> New-Module
Alias           npssc -> New-PSSessionConfigurationFile
Alias           nsn -> New-PSSession
Alias           nv -> New-Variable
Alias           ogv -> Out-GridView
Alias           oh -> Out-Host
Alias           popd -> Pop-Location
Alias           ps -> Get-Process
Alias           pushd -> Push-Location
Alias           pwd -> Get-Location
Alias           r -> Invoke-History
Alias           rbp -> Remove-PSBreakpoint
Alias           rcjb -> Receive-Job
Alias           rcsn -> Receive-PSSession
Alias           rd -> Remove-Item
Alias           rdr -> Remove-PSDrive
Alias           ren -> Rename-Item
Alias           ri -> Remove-Item
Alias           rjb -> Remove-Job
Alias           rm -> Remove-Item
Alias           rmdir -> Remove-Item
Alias           rmo -> Remove-Module
Alias           rni -> Rename-Item
Alias           rnp -> Rename-ItemProperty
Alias           rp -> Remove-ItemProperty
Alias           rsn -> Remove-PSSession
Alias           rsnp -> Remove-PSSnapin
Alias           rujb -> Resume-Job
Alias           rv -> Remove-Variable
Alias           rvpa -> Resolve-Path
Alias           rwmi -> Remove-WMIObject
Alias           sajb -> Start-Job
Alias           sal -> Set-Alias
Alias           saps -> Start-Process
Alias           sasv -> Start-Service
Alias           sbp -> Set-PSBreakpoint
Alias           sc -> Set-Content
Alias           select -> Select-Object
Alias           set -> Set-Variable
Alias           shcm -> Show-Command
Alias           si -> Set-Item
Alias           sl -> Set-Location
Alias           sleep -> Start-Sleep
Alias           sls -> Select-String
Alias           sort -> Sort-Object
Alias           sp -> Set-ItemProperty
Alias           spjb -> Stop-Job
Alias           spps -> Stop-Process
Alias           spsv -> Stop-Service
Alias           start -> Start-Process
Alias           sujb -> Suspend-Job
Alias           sv -> Set-Variable
Alias           swmi -> Set-WMIInstance
Alias           tee -> Tee-Object
Alias           trcm -> Trace-Command
Alias           type -> Get-Content
Alias           wget -> Invoke-WebRequest
Alias           where -> Where-Object
Alias           wjb -> Wait-Job
Alias           write -> Write-Output


PS C:\Users\takk>

Leave a Reply

Your email address will not be published. Required fields are marked *

CAPTCHA