On 9/2/15 11:46 PM, ziyunfei wrote:
> Sorry, I didn't understand your reply. What I'm saying is this: \? is shown
> in printf section:
>
> "Causes printf to expand backslash escape sequences in the corresponding
> argument, except that ‘\c’ terminates output, backslashes in ‘\'’, ‘\"’,
> and ‘\?’ are not removed, and octal escapes beginning with ‘\0’ may contain
> up to four digits.”
>
> but it isn't documented
> in https://www.gnu.org/software/bash/manual/html_node/ANSI_002dC-Quoting.html
> correspondingly
> after \’ and \”.
I guess I see what you're saying: that bash removes the backslash quoting
the `?' when processing $'...' but leaves backslashes escaping other
characters not listed in the description of $'...' unchanged. I can add
that to the documentation.
If that's not what you mean, I guess I don't understand. `printf %b'
expands one set of backslash escapes, and $'...' expands a slightly
different set, since they're trying to serve slightly different purposes
and have different origins. They're separate constructs and are documented
separately.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU [email protected] http://cnswww.cns.cwru.edu/~chet/
