How to find out which symbol is used as a decimal / list separator?

I want to export a table using write.csv. There are 2 flavors of write.csv changing the defaults for the field and the decimal separator.

• write.csv uses . as the decimal point separator and , as the field separator
• write.csv2 uses , as the decimal point separator and ; as the field separator

I want, however, to use the local regional setting (which may be altered from the locale by the user):

Thus, for this user I would like to use . as a decimal separator and ; as a field separator. How could I query these settings from R?

You can query the corresponding registry entries following https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/reg-query

For example:

# get list separator
system('reg query "HKEY_CURRENT_USER\\Control Panel\\International" /v sList', intern = TRUE)

# get decimal symbol
system('reg query "HKEY_CURRENT_USER\\Control Panel\\International" /v sDecimal', intern = TRUE)

Sorry, I'm not familiar with Window's built-in command line cmd & I can't find out how to only extract the value itself. However, this can easily be done in R...

Works on my Windows 10 virtual machine...