string escaping in bash

[Peng Yu]

Hi,

I wondering if there is a simple but robust way to implement string escaping.

Specifically, the string "\n" (a slash and the letter "n") should be
replaced as a newline character, the string "\t" (a slash and the
letter "t") should be replaced as a tab character, and "\\" (two
consecutive slashes should be replaced with a single slash. All other
characters and their preceding slash (if there is) should remain as
is.

If I use a multi-string-replacement strategy, it will not be robust.
For example, if I do it in the order 1) \\ -> \, 2) \n -> newline, \\n
will not be replaced correctly. The result should be "\n" (a slash
followed by the letter "n").

$ x='\\n'; x=${x//\\\\/\\}; x=${x//\\n/$'\n'}; declare -p x
declare -- x="
"

Does anybody have a robust way to implement this in bash?

-- 
Regards,
Peng