builtin printf ignores straight '\c'

[Benno Schulenberg]

Hi,

Bash's printf appears to ignore the \c backslash escape:

$ printf "before \c after \a"
before \c after $
$ type printf
printf is a shell builtin

Of course the Open Group's description of printf
(http://www.opengroup.org/onlinepubs/000095399/utilities/printf.html) 
does not specify that \c in the format string should be interpreted, 
but the builtin echo, and the echo and printf from coreutils, do 
interpret it:

$ echo -e "before \c after \a"
before $
$ type echo
echo is a shell builtin

$ /bin/echo -e "before \c after \a"
before $
$ /usr/bin/printf "before \c after \a"
before $

When \c is provided via the %b conversion specifier, it is 
interpreted:

$ printf "before %b after \a" '\c'
before $      

It makes it seem odd that a straight \c isn't.  (Of course, a 
straight \c is less useful than an indirect one, but still.)

$ bash --version
GNU bash, version 3.2.39(1)-release (i686-pc-linux-gnu)
Copyright (C) 2007 Free Software Foundation, Inc.

Benno