如何在gdb中再次显示core的摘要信息

when loading a core dump into GDB the reason why it crashed automatically is displayed. For example

Program terminated with signal 11, Segmentation fault.

Is there any way to get the information again? The thing is, that I'm writing a script which needs this information. But if the signal is only available after loading the core dump amd I can't access the information later on.

Is there really no command for such an important feature?

void
core_target_open (const char *arg, int from_tty)
{
///....
  p = bfd_core_file_failing_command (core_bfd);
  if (p)
    printf_filtered (_("Core was generated by `%s'.\n"), p);

  /* Clearing any previous state of convenience variables.  */
  clear_exit_convenience_vars ();

  siggy = bfd_core_file_failing_signal (core_bfd);
  if (siggy > 0)
    {
      gdbarch *core_gdbarch = target->core_gdbarch ();

      /* If we don't have a CORE_GDBARCH to work with, assume a native
	 core (map gdb_signal from host signals).  If we do have
	 CORE_GDBARCH to work with, but no gdb_signal_from_target
	 implementation for that gdbarch, as a fallback measure,
	 assume the host signal mapping.  It'll be correct for native
	 cores, but most likely incorrect for cross-cores.  */
      enum gdb_signal sig = (core_gdbarch != NULL
			     && gdbarch_gdb_signal_from_target_p (core_gdbarch)
			     ? gdbarch_gdb_signal_from_target (core_gdbarch,
							       siggy)
			     : gdb_signal_from_host (siggy));

      printf_filtered (_("Program terminated with signal %s, %s"),
		       gdb_signal_to_name (sig), gdb_signal_to_string (sig));
      if (gdbarch_report_signal_info_p (core_gdbarch))
	gdbarch_report_signal_info (core_gdbarch, current_uiout, sig);
      printf_filtered (_(".\n"));

      /* Set the value of the internal variable $_exitsignal,
	 which holds the signal uncaught by the inferior.  */
      set_internalvar_integer (lookup_internalvar ("_exitsignal"),
			       siggy);
    }
///....
}

///@file: gdb-10.1\bfd\elf.c
#if defined (HAVE_PRSTATUS_T)

static bfd_boolean
elfcore_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
{
  size_t size;
  int offset;

  if (note->descsz == sizeof (prstatus_t))
    {
      prstatus_t prstat;

      size = sizeof (prstat.pr_reg);
      offset   = offsetof (prstatus_t, pr_reg);
      memcpy (&prstat, note->descdata, sizeof (prstat));

      /* Do not overwrite the core signal if it
	 has already been set by another thread.  */
      if (elf_tdata (abfd)->core->signal == 0)
	elf_tdata (abfd)->core->signal = prstat.pr_cursig;
      if (elf_tdata (abfd)->core->pid == 0)
	elf_tdata (abfd)->core->pid = prstat.pr_pid;

      /* pr_who exists on:
	 solaris 2.5+
	 unixware 4.2
	 pr_who doesn't exist on:
	 linux 2.[01]
	 */
#if defined (HAVE_PRSTATUS_T_PR_WHO)
      elf_tdata (abfd)->core->lwpid = prstat.pr_who;
#else
      elf_tdata (abfd)->core->lwpid = prstat.pr_pid;
#endif
    }
#if defined (HAVE_PRSTATUS32_T)
  else if (note->descsz == sizeof (prstatus32_t))
    {
      /* 64-bit host, 32-bit corefile */
      prstatus32_t prstat;

      size = sizeof (prstat.pr_reg);
      offset   = offsetof (prstatus32_t, pr_reg);
      memcpy (&prstat, note->descdata, sizeof (prstat));

      /* Do not overwrite the core signal if it
	 has already been set by another thread.  */
      if (elf_tdata (abfd)->core->signal == 0)
	elf_tdata (abfd)->core->signal = prstat.pr_cursig;
      if (elf_tdata (abfd)->core->pid == 0)
	elf_tdata (abfd)->core->pid = prstat.pr_pid;

      /* pr_who exists on:
	 solaris 2.5+
	 unixware 4.2
	 pr_who doesn't exist on:
	 linux 2.[01]
	 */
#if defined (HAVE_PRSTATUS32_T_PR_WHO)
      elf_tdata (abfd)->core->lwpid = prstat.pr_who;
#else
      elf_tdata (abfd)->core->lwpid = prstat.pr_pid;
#endif
    }
#endif /* HAVE_PRSTATUS32_T */
  else
    {
      /* Fail - we don't know how to handle any other
	 note size (ie. data object type).  */
      return TRUE;
    }

  /* Make a ".reg/999" section and a ".reg" section.  */
  return _bfd_elfcore_make_pseudosection (abfd, ".reg",
					  size, note->descpos + offset);
}
#endif /* defined (HAVE_PRSTATUS_T) */

static bfd_boolean
elfcore_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
{
  if (note->descsz == sizeof (elfcore_psinfo_t))
    {
      elfcore_psinfo_t psinfo;

      memcpy (&psinfo, note->descdata, sizeof (psinfo));

#if defined (HAVE_PSINFO_T_PR_PID) || defined (HAVE_PRPSINFO_T_PR_PID)
      elf_tdata (abfd)->core->pid = psinfo.pr_pid;
#endif
      elf_tdata (abfd)->core->program
	= _bfd_elfcore_strndup (abfd, psinfo.pr_fname,
				sizeof (psinfo.pr_fname));

      elf_tdata (abfd)->core->command
	= _bfd_elfcore_strndup (abfd, psinfo.pr_psargs,
				sizeof (psinfo.pr_psargs));
    }
#if defined (HAVE_PRPSINFO32_T) || defined (HAVE_PSINFO32_T)
  else if (note->descsz == sizeof (elfcore_psinfo32_t))
    {
      /* 64-bit host, 32-bit corefile */
      elfcore_psinfo32_t psinfo;

      memcpy (&psinfo, note->descdata, sizeof (psinfo));

#if defined (HAVE_PSINFO32_T_PR_PID) || defined (HAVE_PRPSINFO32_T_PR_PID)
      elf_tdata (abfd)->core->pid = psinfo.pr_pid;
#endif
      elf_tdata (abfd)->core->program
	= _bfd_elfcore_strndup (abfd, psinfo.pr_fname,
				sizeof (psinfo.pr_fname));

      elf_tdata (abfd)->core->command
	= _bfd_elfcore_strndup (abfd, psinfo.pr_psargs,
				sizeof (psinfo.pr_psargs));
    }
#endif

  else
    {
      /* Fail - we don't know how to handle any other
	 note size (ie. data object type).  */
      return TRUE;
    }

  /* Note that for some reason, a spurious space is tacked
     onto the end of the args in some (at least one anyway)
     implementations, so strip it off if it exists.  */

  {
    char *command = elf_tdata (abfd)->core->command;
    int n = strlen (command);

    if (0 < n && command[n - 1] == ' ')
      command[n - 1] = '\0';
  }

  return TRUE;
}

///@file: linux-3.12.6\include\uapi\linux\elfcore.h
struct elf_siginfo
{
	int	si_signo;			/* signal number */
	int	si_code;			/* extra code */
	int	si_errno;			/* errno */
};

/*
 * Definitions to generate Intel SVR4-like core files.
 * These mostly have the same names as the SVR4 types with "elf_"
 * tacked on the front to prevent clashes with linux definitions,
 * and the typedef forms have been avoided.  This is mostly like
 * the SVR4 structure, but more Linuxy, with things that Linux does
 * not support and which gdb doesn't really use excluded.
 * Fields present but not used are marked with "XXX".
 */
struct elf_prstatus
{
#if 0
	long	pr_flags;	/* XXX Process flags */
	short	pr_why;		/* XXX Reason for process halt */
	short	pr_what;	/* XXX More detailed reason */
#endif
	struct elf_siginfo pr_info;	/* Info associated with signal */
	short	pr_cursig;		/* Current signal */
	unsigned long pr_sigpend;	/* Set of pending signals */
	unsigned long pr_sighold;	/* Set of held signals */
#if 0
	struct sigaltstack pr_altstack;	/* Alternate stack info */
	struct sigaction pr_action;	/* Signal action for current sig */
#endif
	pid_t	pr_pid;
	pid_t	pr_ppid;
	pid_t	pr_pgrp;
	pid_t	pr_sid;
	struct timeval pr_utime;	/* User time */
	struct timeval pr_stime;	/* System time */
	struct timeval pr_cutime;	/* Cumulative user time */
	struct timeval pr_cstime;	/* Cumulative system time */
#if 0
	long	pr_instr;		/* Current instruction */
#endif
	elf_gregset_t pr_reg;	/* GP registers */
#ifdef CONFIG_BINFMT_ELF_FDPIC
	/* When using FDPIC, the loadmap addresses need to be communicated
	 * to GDB in order for GDB to do the necessary relocations.  The
	 * fields (below) used to communicate this information are placed
	 * immediately after ``pr_reg'', so that the loadmap addresses may
	 * be viewed as part of the register set if so desired.
	 */
	unsigned long pr_exec_fdpic_loadmap;
	unsigned long pr_interp_fdpic_loadmap;
#endif
	int pr_fpvalid;		/* True if math co-processor being used.  */
};

///@file: linux-3.12.6\fs\binfmt_elf.c
static int fill_note_info(struct elfhdr *elf, int phdrs,
			  struct elf_note_info *info,
			  siginfo_t *siginfo, struct pt_regs *regs)
{
///....
	fill_prstatus(info->prstatus, current, siginfo->si_signo);
///....
}

///@file: linux-3.12.6\include\uapi\linux\elfcore.h
#define ELF_PRARGSZ	(80)	/* Number of chars for args */

struct elf_prpsinfo
{
	char	pr_state;	/* numeric process state */
	char	pr_sname;	/* char for pr_state */
	char	pr_zomb;	/* zombie */
	char	pr_nice;	/* nice val */
	unsigned long pr_flag;	/* flags */
	__kernel_uid_t	pr_uid;
	__kernel_gid_t	pr_gid;
	pid_t	pr_pid, pr_ppid, pr_pgrp, pr_sid;
	/* Lots missing */
	char	pr_fname[16];	/* filename of executable */
	char	pr_psargs[ELF_PRARGSZ];	/* initial part of arg list */
};

///@file: gdb-10.1\bfd\elfcore.h
/*  Core files are simply standard ELF formatted files that partition
    the file using the execution view of the file (program header table)
    rather than the linking view.  In fact, there is no section header
    table in a core file.

    The process status information (including the contents of the general
    register set) and the floating point register set are stored in a
    segment of type PT_NOTE.  We handcraft a couple of extra bfd sections
    that allow standard bfd access to the general registers (.reg) and the
    floating point registers (.reg2).  */

tsecer@harry: cat -n gdb.core.info.recurr.cpp 
     1  int main(int argc, const char *argv[])
     2  {
     3      return *(int*)(0 + 1) = 0;
     4  }
tsecer@harry: gcc -g gdb.core.info.recurr.cpp
tsecer@harry: ./a.out 1 2 3 43 5 4 5 46 5  757 6 7 68  7 87 9 8 9 8 98 0 d f ds fw  as dfs f sd sg s gs
段错误 (core dumped)
tsecer@harry: gdb -c core.11622 --quiet
[New LWP 11622]
Core was generated by `./a.out 1 2 3 43 5 4 5 46 5 757 6 7 68 7 87 9 8 9 8 98 0 d f ds fw as dfs f sd'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00000000004004e7 in ?? ()
(gdb) info proc
exe = './a.out 1 2 3 43 5 4 5 46 5 757 6 7 68 7 87 9 8 9 8 98 0 d f ds fw as dfs f sd'
(gdb) p $_siginfo
$1 = {si_signo = 11, si_errno = 0, si_code = 1, _sifields = {_pad = {1, 0 <repeats 27 times>}, _kill = {si_pid = 1, si_uid = 0}, _timer = {si_tid = 1, si_overrun = 0, si_sigval = {
        sival_int = 0, sival_ptr = 0x0}}, _rt = {si_pid = 1, si_uid = 0, si_sigval = {sival_int = 0, sival_ptr = 0x0}}, _sigchld = {si_pid = 1, si_uid = 0, si_status = 0, si_utime = 0, 
      si_stime = 0}, _sigfault = {si_addr = 0x1, _addr_lsb = 0, _addr_bnd = {_lower = 0x0, _upper = 0x0}}, _sigpoll = {si_band = 1, si_fd = 0}}}
(gdb) p *argv@argc
$4 = {0x7fffe28f15fc "./a.out", 0x7fffe28f1604 "1", 0x7fffe28f1606 "2", 0x7fffe28f1608 "3", 0x7fffe28f160a "43", 0x7fffe28f160d "5", 0x7fffe28f160f "4", 0x7fffe28f1611 "5", 
  0x7fffe28f1613 "46", 0x7fffe28f1616 "5", 0x7fffe28f1618 "757", 0x7fffe28f161c "6", 0x7fffe28f161e "7", 0x7fffe28f1620 "68", 0x7fffe28f1623 "7", 0x7fffe28f1625 "87", 0x7fffe28f1628 "9", 
  0x7fffe28f162a "8", 0x7fffe28f162c "9", 0x7fffe28f162e "8", 0x7fffe28f1630 "98", 0x7fffe28f1633 "0", 0x7fffe28f1635 "d", 0x7fffe28f1637 "f", 0x7fffe28f1639 "ds", 0x7fffe28f163c "fw", 
  0x7fffe28f163f "as", 0x7fffe28f1642 "dfs", 0x7fffe28f1646 "f", 0x7fffe28f1648 "sd", 0x7fffe28f164b "sg", 0x7fffe28f164e "s", 0x7fffe28f1650 "gs"}
(gdb)