FORMAT controls the output as in C printf. Interpreted sequences are:
\"
double quote
\NNN
character with octal value NNN (1 to 3 digits)
\\
backslash
\a
alert (BEL)
\b
backspace
\c
produce no further output
\f
form feed
\n
new line
\r
carriage return
\t
horizontal tab
\v
vertical tab
\xHH
byte with hexadecimal value HH (1 to 2 digits)
\uHHHH
Unicode (ISO/IEC 10646) character with hex value HHHH (4 digits)
\UHHHHHHHH
Unicode character with hex value HHHHHHHH (8 digits)
%%
a single %
%b
ARGUMENT as a string with `\' escapes interpreted,
except that octal escapes are of the form \0 or \0NNN
and all C format specifications ending with one of diouxXfeEgGcs, with
ARGUMENTs converted to proper type first. Variable widths are handled.
NOTE: your shell may have its own version of printf, which usually supersedes
the version described here. Please refer to your shell's documentation
for details about the options it supports.