The `s6-quote` program

s6-quote quotes a string and writes it to stdout.

Interface

     s6-quote [ -n ] [ -u ] [ -d delim ] string

s6-quote quotes string, putting it inside double quotes and escaping all dubious characters
It writes the quoted string to stdout and exits 0

-n : do not print a trailing newline
-u : do not put string inside double quotes, only escape characters if needed
-d delim : use the first character of delim as a quote character, instead of double quotes

Quoted strings are guaranteed to be pure printable ASCII, without control characters.
Quoted strings can be unquoted via the s6-unquote or s6-unquote-filter programs.
Quoted strings are suitable for interpretation by execlineb.