_ D_GUN_SOURCE ?? And a few small issues

_ D_GUN_SOURCE ?? And a few minor issues-general Linux technology-Linux programming and kernel information, the following is a detailed description. Haha! I just got started with linux C language programming! Thank you!

Besides, under F7, gcc-g-D_GUN_SOURCE dd. c-o hello
# Include

Static void fun (void)
{
Char * p = 0;
* P = '! ';
}

Int main ()
{
Fun ();
Return 0;
}

This program is incorrect, but the following occurs when you use ls-l core (ls: cannot access core: No file or directory) gdb./hello core
========================================================== ================
GNU gdb Red Hat Linux (6.6-15. fc7rh)
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
Welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-redhat-linux-gnu "...
Using host libthread_db library "/lib/libthread_db.so.1 ".
/Home/k/Desktop/c/core: No such file or directory.
(Gdb)

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[ This post was last edited by yorktown]