GDB Cheat Sheet

The following is a collection of bindings and tips for GDB. I highly recommend installing gef for the best experience

Tips

• Set memory on stack with set {int}<addr> = <val>

Without debug flags

• r: run
• c: continue from break point
• si: step instruction
• until [location]: run until next instruction or location
• finish: run until stack frame [function] returns
• jump *<address>: resume execution at address
• set var=<expr>: evaluate expr and set it
• p [/f] [expr]: show value of expr
  • x: hex
  • d: signed decimal
  • u: unsigned decimal
  • o: octal
  • t: binary
  • a: address
  • c: character
  • f: floating point
• x [/Nuf] [expr]: examine memory at location
  • N: count of units to display
  • u: unit size
    • b: bytes
    • h: half words (two bytes)
    • w: word (four bytes)
    • g: giant word (eight bytes)
  • f: printing format, any print format or
    • s: null terminated string
    • i: machine instructions
• d: Print on each step
• disas [addr]: display memory as machine instructions
  • disas *main to show main function
• s: execute next instruction

With debug flags

• n: continue until next line is reched
• jump <line>: resume execution at line
• list to print lines around breakpoint