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

[Andrew Cagney <ac131313@redhat.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