Why am I getting "Can't find string terminator "'" anywhere before EOF at -e line 1" when I try to run a Perl one-liner on Windows?

You're missing a decent shell with sane and well-defined quoting rules. On Windows, only the double quote is considered a quote, and the escaping rules are poorly defined and inconsistent. Try:

perl -e "print qq{Hello World \n}"

I strongly recommend avoiding anything but the very simplest one-liners on Windows. (Another problem with Windows one-liners is that the Windows shell doesn't expand wildcards. If you use *.txt on the command line, it'll look for a file named literally *.txt. You'll run into that later.)

On Windows, what you typed is equivalent to:

perl -e "'print" "Hello World \n'"

That is, the code Perl is trying to execute is 'print with @ARGV containing the single string Hello World \n'. (That's not a newline, that's a backslash followed by n).

On Windows, the quotation marks should be reversed. So, rather than:

C:\Perl>perl -e 'print "Hello World \n"'

it should be:

C:\Perl>perl -e "print 'Hello World \n'"

(attribution Learning Perl, 6th edition, p. 295)

perl -e "$a=2; print(\"$a \n \");"