Create regular expression from string using sprintf format and handlebars
http://www.cplusplus.com/reference/cstdio/printf/
%[flags][width][.precision][length]specifier
specifier Output Example d or i Signed decimal integer 392 u Unsigned decimal integer 7235 o Unsigned octal 610 x Unsigned hexadecimal integer 7fa X Unsigned hexadecimal integer (uppercase) 7FA f Decimal floating point, lowercase 392.65 F Decimal floating point, uppercase 392.65 e Scientific notation (mantissa/exponent), lowercase 3.9265e+2 E Scientific notation (mantissa/exponent), uppercase 3.9265E+2 g Use the shortest representation: %e or %f 392.65 G Use the shortest representation: %E or %F 392.65 a Hexadecimal floating point, lowercase -0xc.90fep-2 A Hexadecimal floating point, uppercase -0XC.90FEP-2 c Character a s String of characters sample p Pointer address b8000000 n Nothing printed. The corresponding argument must be a pointer to a signed int. The number of characters written so far is stored in the pointed location. % A % followed by another % character will write a single % to the stream. %