Re: [RFA/RFC] Problem with '!' escaping with zsh/bash/ksh

[Andrew Cagney <ac131313 at redhat dot com>]

Joel, testcase?

I was going to suggest gdb.base/args.exp but someone's already added that.
Consider an addition to that existing test case pre-approved (and any 
other evil combinations you come up with).

Anyway, as best I can tell the technical issues were resolved, so yes, 
approved.

Andrew


> > I think you are right to say that "\a" is equivalent to "a" in general.
> > However, in our case, the argument is quoted, specifically single-quoted.
> > And it seems to make a big difference: with single quotes, the
> > expression is no longer evaluated. That's why the backslash becomes
> > harmful.
> >
> > Daniel said:
>
> > > By the way... what would the general reaction be to supporting exec'ing
> > > the program directly instead of through the shell?  At least as an
> > > option, since it would be a bit of an interface/quoting change?
>
> > I think that'd be very nice, actually. Can somebody tell me what the
> > advantage of forking via a shell is?
>
>
> Globbing, primarily; and it handles some complexities of quoting (but
> introduces others!).
>
> Me, I think on modern systems we can just do argument splitting
> and globbing ourselves if we want to.  It's more efficient and less
> fragile.

Hmm, this came up ``recently'', "inferior.h" contains:

/* If STARTUP_WITH_SHELL is set, GDB's "run"
   will attempts to start up the debugee under a shell.
   This is in order for argument-expansion to occur. E.g.,
   (gdb) run *
   The "*" gets expanded by the shell into a list of files.
   While this is a nice feature, it turns out to interact badly
   with some of the catch-fork/catch-exec features we have added.
   In particular, if the shell does any fork/exec's before
   the exec of the target program, that can confuse GDB.
   To disable this feature, set STARTUP_WITH_SHELL to 0.
   To enable this feature, set STARTUP_WITH_SHELL to 1.
   The catch-exec traps expected during start-up will
   be 1 if target is not started up with a shell, 2 if it is.
   - RT
   If you disable this, you need to decrement
   START_INFERIOR_TRAPS_EXPECTED in tm.h. */
#define STARTUP_WITH_SHELL 1
#if !defined(START_INFERIOR_TRAPS_EXPECTED)
#define START_INFERIOR_TRAPS_EXPECTED   2
#endif

http://sources.redhat.com/ml/gdb-patches/2002-04/msg00759.html

Andrew