如何将字符转换为关联的转义序列？

Question

I need to transform escape sequences contained in non-literal strings (so that they are split in more characters, the first one being \\ and the others being just n , r or even octal codes etc.) to the actual character represented by that escape sequence.

My first thought was it could be possible using a macro (like #define to_escape(x) '\\(x)' which doesn't work), but I wonder if there actually is a way like that and if there are better ways.

Of course I could use a simple switch statement for escapes like \\a , \\f and similars, but then how would I handle all the octal and hexadecimal escapes?

Answer 1

you can go for this byte allocation

\'  single quote            byte 0x27 in ASCII encoding
\"  double quote            byte 0x22 in ASCII encoding
\?  question mark           byte 0x3f in ASCII encoding
\\  backslash               byte 0x5c in ASCII encoding
\a  audible bell            byte 0x07 in ASCII encoding
\b  backspace               byte 0x08 in ASCII encoding
\f  form feed - new page    byte 0x0c in ASCII encoding
\n  line feed - new line    byte 0x0a in ASCII encoding
\r  carriage return         byte 0x0d in ASCII encoding
\t  horizontal tab          byte 0x09 in ASCII encoding
\v  vertical tab            byte 0x0b in ASCII encoding

check if their addresses match their hexa-addresses and you can retrieve the following character.