Escape sequences are processed.
These escape sequences are understood:
‘\a’, ‘\b’, ‘\e’, ‘\f’, ‘\n’, ‘\r’,
‘\xhex-digits’, ‘\octal-digits’.
Other than that, a backslash is ignored.
A directive consists of
a ‘%’ character,
optionally a flag character ‘-’,
optionally a flag character ‘0’,
optionally a width specification (a nonnegative integer),
and finally a specifier:
‘s’ that formats a string, ‘c’ that formats a character,
‘d’ and ‘u’, that format a (signed/unsigned) integer in decimal,
or ‘x’, that formats an unsigned integer in hexadecimal.
There is also the directive ‘%%’, that produces a single percent character.