PowerShell functions that return true/false

You can use return statements in PowerShell:

Function Do-Something {    $return = Test-Path c:\dev\test.txt    return $return}Function OnlyTrue {    if (Do-Something) {        "Success"    } else {        "Fail"    }}OnlyTrue

The output is Success if the file exists and Fail if it doesn't.

One caveat is that PowerShell functions return everything that's not captured. For instance, if I change the code of Do-Something to:

Function Do-Something {    "Hello"    $return = Test-Path c:\dev\test.txt    return $return}

Then the return will always be Success, because even when the file does not exist, the Do-Something function returns an object array of ("Hello", False). Have a look in Boolean Values and Operators for more information on booleans in PowerShell.

Don't use True or False, instead use $true or $false

function SuccessConnectToDB { param([string]$constr) $successConnect = .\psql -c 'Select version();' $constr    if ($successConnect) {        return $true;    }    return $false;}

Then call it in a nice clean way:

if (!(SuccessConnectToDB($connstr)) {    exit  # "Failure Connecting"}

You'd do something like this. The Test command uses the automatic variable '$?'. It returns true/false if the last command completed successfully (see the about_Automatic_Variables topic for more information):

Function Test-Something {     Do-Something     $? } Function OnlyTrue {     if(Test-Something) { ... } }