I am only 2 days into PowerShell after watching Jeff Hicks’s 3-part PowerShell Essentials videos, so I apologize for the newbie obvious mistakes (20+ years programming, none in PowerShell !!). I think my issue is with syntax placement.
I’m trying to write a simple script to turn on WinRM on remote domain computers using the script below. In the output window, the computers UT0291, PD3697, and PDCM06 do not ping, but the logic drops each object into the “True” section and I don’t get the “CANNOT ping” message I expect when $tc evaluates to “false”. I’ve run the “Test-Connection” command on all 3 individually in the command window and each one returns “False”. Definitely won’t be my last post for help !! Thanks everyone.
Thank you both, that did it. I’m guessing I should using the “=” type operators for arithmetic evaluations and “-eq” for boolean and string comparisons.
Rob, in your suggestions, the line "foreach ($cname in $dcomps) { ", I have seen this type of statement in many examples. However, where is the “$cname” variable declared ? Is that just some variable that is created when the statement is run ? Could I have used "foreach ($dogpile in $dcomps){ " and then reference the “$dogpile” variable ? And I assume these are variables and not objects, and therefore do not have properties, like “$cname.value” or "$dogpile.value, correct ?
Ah, to be such a newbie again, I forgot what it was like to to be “programmer dumb” !! Thanks again.
Yes, that is just a placeholder variable that is defined by you.
This is a ‘it depends’. Almost everything is an ‘object’. Even if in the exammple above you are working with strings that have properties (e.g. Length) and methods.
$dComps = 'www.google.com', 'www.badgoogle.com', 'www.microsoft.com'
foreach ($dogpile in $dcomps) {
'Length: {0}' -f $dogpile.Length
$dogPile.Split('.') #Split into an array
}
#foreach of a PSObject that has properties
foreach ($proc in Get-Process | Select -First 5) {
'Processing {0} with id {1}' -f $proc.Name, $proc.Id
}
You can use GetType() to see what the type is and Get-Member to see what properties\methods exist for an object:
PS C:\Users\rasim> $dogpile.GetType()
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True String System.Object
PS C:\Users\rasim> $dogpile | Get-Member
TypeName: System.String
Name MemberType Definition
---- ---------- ----------
Clone Method System.Object Clone(), System.Object ICloneable.Clone()
CompareTo Method int CompareTo(System.Object value), int CompareTo(string strB), int IComparable.CompareTo(System.Object obj), int IComparable[string].CompareTo(string other)
Contains Method bool Contains(string value)
CopyTo Method void CopyTo(int sourceIndex, char[] destination, int destinationIndex, int count)
EndsWith Method bool EndsWith(string value), bool EndsWith(string value, System.StringComparison comparisonType), bool EndsWith(string value, bool ignoreCase, cultureinfo culture)
Equals Method bool Equals(System.Object obj), bool Equals(string value), bool Equals(string value, System.StringComparison comparisonType), bool IEquatable[string].Equals(string other)
GetEnumerator Method System.CharEnumerator GetEnumerator(), System.Collections.IEnumerator IEnumerable.GetEnumerator(), System.Collections.Generic.IEnumerator[char] IEnumerable[char].GetEnumerator()
GetHashCode Method int GetHashCode()
GetType Method type GetType()
GetTypeCode Method System.TypeCode GetTypeCode(), System.TypeCode IConvertible.GetTypeCode()
IndexOf Method int IndexOf(char value), int IndexOf(char value, int startIndex), int IndexOf(string value), int IndexOf(string value, int startIndex), int IndexOf(string value, int startIndex, int count), i...
IndexOfAny Method int IndexOfAny(char[] anyOf), int IndexOfAny(char[] anyOf, int startIndex), int IndexOfAny(char[] anyOf, int startIndex, int count)
Insert Method string Insert(int startIndex, string value)
IsNormalized Method bool IsNormalized(), bool IsNormalized(System.Text.NormalizationForm normalizationForm)
LastIndexOf Method int LastIndexOf(char value), int LastIndexOf(char value, int startIndex), int LastIndexOf(string value), int LastIndexOf(string value, int startIndex), int LastIndexOf(string value, int start...
LastIndexOfAny Method int LastIndexOfAny(char[] anyOf), int LastIndexOfAny(char[] anyOf, int startIndex), int LastIndexOfAny(char[] anyOf, int startIndex, int count)
Normalize Method string Normalize(), string Normalize(System.Text.NormalizationForm normalizationForm)
PadLeft Method string PadLeft(int totalWidth), string PadLeft(int totalWidth, char paddingChar)
PadRight Method string PadRight(int totalWidth), string PadRight(int totalWidth, char paddingChar)
Remove Method string Remove(int startIndex, int count), string Remove(int startIndex)
Replace Method string Replace(char oldChar, char newChar), string Replace(string oldValue, string newValue)
Split Method string[] Split(Params char[] separator), string[] Split(char[] separator, int count), string[] Split(char[] separator, System.StringSplitOptions options), string[] Split(char[] separator, int...
StartsWith Method bool StartsWith(string value), bool StartsWith(string value, System.StringComparison comparisonType), bool StartsWith(string value, bool ignoreCase, cultureinfo culture)
Substring Method string Substring(int startIndex), string Substring(int startIndex, int length)
ToBoolean Method bool IConvertible.ToBoolean(System.IFormatProvider provider)
ToByte Method byte IConvertible.ToByte(System.IFormatProvider provider)
ToChar Method char IConvertible.ToChar(System.IFormatProvider provider)
ToCharArray Method char[] ToCharArray(), char[] ToCharArray(int startIndex, int length)
ToDateTime Method datetime IConvertible.ToDateTime(System.IFormatProvider provider)
ToDecimal Method decimal IConvertible.ToDecimal(System.IFormatProvider provider)
ToDouble Method double IConvertible.ToDouble(System.IFormatProvider provider)
ToInt16 Method int16 IConvertible.ToInt16(System.IFormatProvider provider)
ToInt32 Method int IConvertible.ToInt32(System.IFormatProvider provider)
ToInt64 Method long IConvertible.ToInt64(System.IFormatProvider provider)
ToLower Method string ToLower(), string ToLower(cultureinfo culture)
ToLowerInvariant Method string ToLowerInvariant()
ToSByte Method sbyte IConvertible.ToSByte(System.IFormatProvider provider)
ToSingle Method float IConvertible.ToSingle(System.IFormatProvider provider)
ToString Method string ToString(), string ToString(System.IFormatProvider provider), string IConvertible.ToString(System.IFormatProvider provider)
ToType Method System.Object IConvertible.ToType(type conversionType, System.IFormatProvider provider)
ToUInt16 Method uint16 IConvertible.ToUInt16(System.IFormatProvider provider)
ToUInt32 Method uint32 IConvertible.ToUInt32(System.IFormatProvider provider)
ToUInt64 Method uint64 IConvertible.ToUInt64(System.IFormatProvider provider)
ToUpper Method string ToUpper(), string ToUpper(cultureinfo culture)
ToUpperInvariant Method string ToUpperInvariant()
Trim Method string Trim(Params char[] trimChars), string Trim()
TrimEnd Method string TrimEnd(Params char[] trimChars)
TrimStart Method string TrimStart(Params char[] trimChars)
Chars ParameterizedProperty char Chars(int index) {get;}
Length Property int Length {get;}
The “flexibility” of PowerShell and it’s ability to perform the same task in a multitude of ways is a little
“mind-boggling” !! Other “rigid” languages are little easier (for me at least) to figure out and troubleshoot. Once you know
how to structure the syntax, that was pretty much it. I like the flexibility of PowerShell, it is really powerful, I just need more
practice and training…“baby steps”…although “baby steps” are at time very frustrating when you can write code in another
language with your eyes closed !!
Since you started coding in PowerShell. I can suggest you to use debug option in Powershell ISE (or other IDE which support Powershell Script Development).
It really helps you to figure out the issue.
In the above case if you have marked a breakpoint on code if ($tc = $true) {} and run the script on debug mode. When the logic reaches the line ,execute it and just hover the mouse above the $tc variable, so you can see “True” value getting assigned to the $tc variable.
So this makes you understand it is not doing the comparison.
Powerhell is not really a programming language, it’s a scripting platform that you can use for programming tasks, but it was built for administrators that needed to perform tasks. Programming languages are more strict because you want consistent code for the compiler or for other developers. While the rules are loose, there are style recommendations to make code easier to read, like this GitHub - PoshCode/PowerShellPracticeAndStyle: The Unofficial PowerShell Best Practices and Style Guide
Thanks, Rob, that makes sense. I find a lot of similarities between “script” code and “language” code. I think my biggest hurdle is going to be syntax. For example, I just watched a video which references the “Switch” function, which seems to act a lot like a “Case” statement in programming.
And thank you Sunish, I have discovered the “debug” options. In programming, the “step” function is most helpful, so I think I will find it useful as I learn.
I’m seeing that most of my work will be utilizing “WMI” and “CIM” commands to manage domain computers. We also have a Govt Office 365 tenant, so I’m delving into the world of using powershell to manage MS exchange accounts in Office 365, such as group memberships, account management etc.
