Differences between single and double quotes in CMD

Question

I have a powershell file that replaces an IP in a config file. The powershell takes in three parameters:

1. file name ('C:\Program Files (x86)\app\app.conf')
2. IP to replace
3. new IP

Since we are dependent on using a batch file for our service to process the task, I wrote a batch script that simply takes three parameters and posts that to the powershell script.

We use batch file for calling and parsing the parameter: ($ just used to represent variables)

changeip.bat '$filepath' $oldip $newip

This fails, but I don't understand why. I've tried using double quotes instead of single quotes around $filepath and it worked.

How can the whitespace in $filepath be understood by double quotes and not single quotes?

Answer 1

The short answer is that CMD doesn't treat single quotes as anything but a regular character. It's not a pair/group like double quotes.

The only place where the single quote has any special meaning is in a FOR /F loop, where you are specifying a command to run and iterate over the output.

FOR /F %%d IN ('DIR /S /B C:\Windows') DO @ECHO File: %%d

FOR /F has an option to use backticks instead, in case you need to pass single quotes to the called process, but this is unrelated to your question.