How do you escape characters in heredoc?

Question

I'm working with a bash script trying to stop it from attempting to replace variables inside my heredoc. How do set a heredoc to either A) escape the variable names instead of parsing them or B) return the entire string untouched?

cat > /etc/nginx/sites-available/default_php <<END
server {
    listen 80 default;
    server_name _;
    root /var/www/$host; <--- $host is a problem child
}
END

As is, when I it finishes injecting it into a file I'm left with this:

server {
    listen 80 default;
    server_name _;
    root /var/www/;
}

Answer 1

From the bash(1) man page:

If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded.

cat > /etc/nginx/sites-available/default_php <<"END"

Answer 2

Just with a backslash:

cat > /tmp/boeboe <<END
server {
    listen 80 default;
    server_name _;
    root /var/www/\$host';
}
END

Answer 3

@Xeoncross (and all landing here via search engine results) : it is possible to disable variable substitution by single-quoting the stop token :

cat > /tmp/boeboe << 'END'
server {
    listen 80 default;
    server_name _;
    root /var/www/$host;
}

# Example : here is another occurrence of '$host' which won't be substituted either
# When single-quoting the stop token, you don't have to escape all '$myVariable' anymore
END