Function: _def_prompt
Class: default
Section: default
C-Name: sd_prompt
Prototype:
Help:
Doc: a string that will be printed as
 prompt. Note that most usual escape sequences are available there: \b{e} for
 Esc, \b{n} for Newline, \dots, \kbd{\bs\bs} for \kbd{\bs}. Time expansion is
 performed.

 This string is sent through the library function \tet{strftime} (on a
 Unix system, you can try \kbd{man strftime} at your shell prompt). This means
 that \kbd{\%} constructs have a special meaning, usually related to the time
 and date. For instance, \kbd{\%H} = hour (24-hour clock) and \kbd{\%M} =
 minute [00,59] (use \kbd{\%\%} to get a real \kbd{\%}).

 If you use \kbd{readline}, escape sequences in your prompt will result in
 display bugs. If you have a relatively recent \kbd{readline} (see the comment
 at the end of \secref{se:def,colors}), you can brace them with special sequences
 (\kbd{\bs[} and \kbd{\bs]}), and you will be safe. If these just result in
 extra spaces in your prompt, then you'll have to get a more recent
 \kbd{readline}. See the file \kbd{misc/gprc.dft} for an example.

 \emacs {\bf Caution}: PariEmacs needs to know about the prompt pattern to
 separate your input from previous \kbd{gp} results, without ambiguity. It is
 not a trivial problem to adapt automatically this regular expression to an
 arbitrary prompt (which can be self-modifying!). See PariEmacs's
 documentation.

 The default value is \kbd{"? "}.
