Notes - PowerShell & CMD

Tips

How to open terminal in the current folder?

1. Right-click the folder > Open in Terminal
2. From Windows Explorer address bar > wt -d .

Execute multiple commands on one line

Windows CMD: go build | try

* &: separate multiple commands on one command line.
* &&: run the command following && only if the command preceding the symbol is successful. `mkdir -p newApp && cd newApp`
* ||: run the command following || only if the command preceding || fails.

For Powershell or Bash(semicolon):

New version:

• go build && .\try.exe: Execute the second command only if the first one succeeds
• go build || .\try.exe: Execute the second command only if the first one fails

Old version:

• go build; .\try.exe: Execute the first command, then second command
• go build; if ($?) {.\server.exe}: To execute the second command only if the first command is succeed

How to find the location of an executable file?

From command line:

G:\>where hugo
C:\Andrew\prg\bin\hugo.bat

From PowerShell:

PS C:\Andrew\prj\blog> Get-Command hugo
CommandType     Name       Version    Source
-----------     ----       -------    ------
Application     hugo.bat   0.0.0.0    C:\Andrew\prg\bin\hugo.bat

How to change character encoding?

Beginning in PowerShell 5.1, the redirection operators (> and ») call the Out-File cmdlet, which is UTF-16 encoding by default. To change the encoding to UTF-8:

$PSDefaultParameterValues['Out-File:Encoding'] = 'utf8'
.\plan-b.exe | Out-File plan.txt -encoding utf8

How to get PowerShell version

> $PSVersionTable

Environment Variables

How to show environment variables?

Show all environment variables:

• PowerShell: dir env:
• CMD: SET

Show one environment variable:

• PowerShell: $Env:METRICSID
• CMD: SET METRICSID

How to set an environment variable?

PowerShell:

• $Env:METRICSID = "MYID"
• $Env:METRICSID += "!" // MYID!
• $Env:PATH += ";C:\bin"

CMD:

• SET METRICSID="MYID" // Only this session
• SETX METRICSID MYID // Global

How to save environment variable into a text file?

$Env:PATH >> path.txt

How to remove an environment variable?

Set the variable as empty string will remove it.

• $Env:METRICSID = ""

How to display environment variables?

// dir and gci are both aliases for Get-ChildItem
// dir env:
PS > gci env: | where name -like 'METRICS*'
Name                           Value
----                           -----
METRICSID                      CORPORATE\mynameid
METRICSPASSWORD                MYPASSWORD