Powershell 变量替换与 Start-Process 和 ArgumentList

Question

I have this bit of powershell code that gets the FQDN and saves it to a variable...works great:

$FQDN=(Get-WmiObject win32_computersystem).DNSHostName.ToLower()+"."+(Get-WmiObject win32_computersystem).Domain

LogWrite "[+] The system fully qualified hostname has been detected as: $FQDN"

However, when I go to insert the string of the FQDN variable, I can not get it to work correctly. I have tried back ticks, double and single quotes with no success:

Start-Process -Wait $OUTPATH64 -ArgumentList '/s /v"/qn INSTALLDIR=\"C:\Program Files\IBM\WinCollect\" LOG_SOURCE_AUTO_CREATION_ENABLED=TRUE LOG_SOURCE_AUTO_CREATION_PARAMETERS=""Component1.AgentDevice=DeviceWindowsLog&Component1.Action=create&Component1.LogSourceName=REPLACEME&Component1.LogSourceIdentifier=REPLACEME&Component1.Dest.Name=test.domain.com&Component1.Dest.Hostname=test.domain.com&Component1.Dest.Port=514&Component1.Dest.Protocol=TCP&Component1.Log.Security=true&Component1.Log.System=true&Component1.Log.Application=true&Component1.Log.DNS+Server=false&Component1.Log.File+Replication+Service=false&Component1.Log.Directory+Service=false&Component1.RemoteMachinePollInterval=3000&Component1.EventRateTuningProfile=Default+(Endpoint)&Component1.MinLogsToProcessPerPass=100&Component1.MaxLogsToProcessPerPass=150"""'

Where you see the "REPLACEME" string, I need that replaced with the $FQDN variable string. Whenever I use backticks $FQDN or with double quotes"$FQDN" or even single quotes '$FQDN' I get the literal string of "$FQDN" and the snippet of code does not actually do the variable replacement.

What am I missing here? I have also even tried backticks double quotes "$FQDN" . I want the REPLACEME string to be replaced with something like the actual hostname + domain like hostname.domain.com or what is set in the $FQDN variable. The ArgumentList quotes need to stay the same as I can only get my command to work correctly by quoting the ArgumentList the way it is starting with a ' and ending with """'. Any help would be greatly appreciated.

Answer 1

Single -quoted strings ( '...' ) in PowerShell are verbatim (literal) strings in PowerShell - by design, no expansion (interpolation) of embedded variable references or expression is performed.

To get the latter, you must use an expandable string, which is double -quoted ( "..." ); eg,
"...SourceName=$FQDN&Component1... "

Since your string contains embedded " characters, it is simplest to us the here-string variant of an expandable string ( @"<newline>...<newline>"@ ):

Start-Process -Wait $OUTPATH64 -ArgumentList @"
/s /v"/qn INSTALLDIR=\"C:\Program Files\IBM\WinCollect\" LOG_SOURCE_AUTO_CREATION_ENABLED=TRUE LOG_SOURCE_AUTO_CREATION_PARAMETERS=""Component1.AgentDevice=DeviceWindowsLog&Component1.Action=create&Component1.LogSourceName=$FQDN&Component1.LogSourceIdentifier=$FQDN&Component1.Dest.Name=test.domain.com&Component1.Dest.Hostname=test.domain.com&Component1.Dest.Port=514&Component1.Dest.Protocol=TCP&Component1.Log.Security=true&Component1.Log.System=true&Component1.Log.Application=true&Component1.Log.DNS+Server=false&Component1.Log.File+Replication+Service=false&Component1.Log.Directory+Service=false&Component1.RemoteMachinePollInterval=3000&Component1.EventRateTuningProfile=Default+(Endpoint)&Component1.MinLogsToProcessPerPass=100&Component1.MaxLogsToProcessPerPass=150"""
"@

If you used a regular double-quoted string ( "..." ), you'd have to escape the embedded " characters as `" (or "" ).

See the bottom section of this answer for more information about PowerShell's string literals; the official help topic is about_Quoting_Rules .

Answer 2

This is how it should work using back ticks:

Start-Process -Wait $OUTPATH64 -ArgumentList "/s /v /qn INSTALLDIR=`"C:\Program Files\IBM\WinCollect\`" LOG_SOURCE_AUTO_CREATION_ENABLED=TRUE LOG_SOURCE_AUTO_CREATION_PARAMETERS=`"Component1.AgentDevice=DeviceWindowsLog&Component1.Action=create&Component1.LogSourceName=$FQDN&Component1.LogSourceIdentifier=$FQDN&Component1.Dest.Name=test.domain.com&Component1.Dest.Hostname=test.domain.com&Component1.Dest.Port=514&Component1.Dest.Protocol=TCP&Component1.Log.Security=true&Component1.Log.System=true&Component1.Log.Application=true&Component1.Log.DNS+Server=false&Component1.Log.File+Replication+Service=false&Component1.Log.Directory+Service=false&Component1.RemoteMachinePollInterval=3000&Component1.EventRateTuningProfile=Default+(Endpoint)&Component1.MinLogsToProcessPerPass=100&Component1.MaxLogsToProcessPerPass=150`""