wei ~/Dropbox/CSCI531 Applied Cryptography/hw2 $ ggdb hw2
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Reading symbols from hw2...done.
(gdb) b hw2.c:20
Breakpoint 1 at 0x100000629: file hw2.c, line 20.
(gdb) run
Starting program: /Users/wei/Dropbox/CSCI531 Applied Cryptography/hw2/hw2
warning: Could not open OSO archive file "/BinaryCache/Libsyscall/Libsyscall-2422.110.17~1/Symbols/BuiltProducts/libsystem_kernel.a"
warning: `/private/var/tmp/Libsyscall/Libsyscall-2422.110.17~1/Libsyscall.build/Libsyscall_dynamic.build/Objects-normal/x86_64/_libc_funcptr.o': can't open to read symbols: No such file or directory.
warning: `/private/var/tmp/Libsyscall/Libsyscall-2422.110.17~1/Libsyscall.build/Libsyscall_dynamic.build/Objects-normal/x86_64/kernel_vers.o': can't open to read symbols: No such file or directory.
warning: `/private/var/tmp/Libsyscall/Libsyscall-2422.110.17~1/Libsyscall.build/Libsyscall_dynamic.build/Objects-normal/x86_64/memcpy.o': can't open to read symbols: No such file or directory.
warning: `/private/var/tmp/Libsyscall/Libsyscall-2422.110.17~1/Libsyscall.build/Libsyscall_dynamic.build/Objects-normal/x86_64/strcmp.o': can't open to read symbols: No such file or directory.
warning: `/private/var/tmp/Libsyscall/Libsyscall-2422.110.17~1/Libsyscall.build/Libsyscall_dynamic.build/Objects-normal/x86_64/strlcpy.o': can't open to read symbols: No such file or directory.
warning: `/private/var/tmp/Libsyscall/Libsyscall-2422.110.17~1/Libsyscall.build/Libsyscall_dynamic.build/Objects-normal/x86_64/strlen.o': can't open to read symbols: No such file or directory.
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libatomics_normal.a"
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libcachecontrol_normal.a"
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libos_normal.a"
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libsetjmp_normal.a"
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libsimple_normal.a"
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libstring_normal.a"
warning: Could not open OSO archive file "/BinaryCache/libplatform/libplatform-24.90.1~2/Symbols/libucontext_normal.a"
warning: `/private/var/tmp/libplatform/libplatform-24.90.1~2/libplatform.build/libsystem_platform.build/Objects-normal/x86_64/init.o': can't open to read symbols: No such file or directory.

Breakpoint 1, main (argc=1, argv=0x7fff5fbffaf0) at hw2.c:20
20	    FILE *target_file2 = NULL;
(gdb) q
A debugging session is active.

	Inferior 1 [process 31877] will be killed.

Quit anyway? (y or n) y
wei ~/Dropbox/CSCI531 Applied Cryptography/hw2 $