GDB Basics Cheatsheet

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gdb ./path-to-binary

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gdb -silent `pidof <binary-name>`

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gdb -tui

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(gdb) b main // Breaks at main()
(gdb) break strcpy // Breaks at strcpy()

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(gdb) info b

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(gdb) c

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(gdb) s

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(gdb) print $esp

(gdb) x/5x $esp-10 // in Hex
(gdb) x/5s $esp-10 //String
(gdb) x/5d $esp-10 //Decimal
(gdb) x/5i $esp-10 //Assembly Instructions

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(gdb) list

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(gdb) where

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(gdb) info file

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(gdb) info functions

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(gdb) disas <func-name>

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(gdb) disas strcpy
Dump of assembler code for function strcpy:
0x42079dd0 <strcpy+0>:  push   %ebp
0x42079dd1 <strcpy+1>:  mov    %esp,%ebp
0x42079dd3 <strcpy+3>:  push   %esi
0x42079dd4 <strcpy+4>:  mov    0x8(%ebp),%esi
0x42079dd7 <strcpy+7>:  mov    0xc(%ebp),%edx
0x42079dda <strcpy+10>: mov    %esi,%eax
0x42079ddc <strcpy+12>: sub    %edx,%eax
0x42079dde <strcpy+14>: lea    0xffffffff(%eax),%ecx
0x42079de1 <strcpy+17>: jmp    0x42079df0 <strcpy+32>
0x42079de3 <strcpy+19>: nop
0x42079de4 <strcpy+20>: nop
0x42079dfb <strcpy+43>: mov    %esi,%eax
0x42079dfd <strcpy+45>: pop    %esi
0x42079dfe <strcpy+46>: pop    %ebp
0x42079dff <strcpy+47>: ret
End of assembler dump.