Start
  gdb
  gdb <file>


Run and Stop
  help                      Get information about gdb
  quit                      Exit gdb
  run                       Run program
  run 1 2 3                 Run program with command-line arguments 1 2 3
  run < in.txt              Run program with input redirected from in.txt
  kill                      Stop the program
  Control-D                 Exit gdb
  Control-C                 Stop the currently running gdb command
                            (Does not exit GDB.)
  make                      Run make to rebuild without leaving gdb


Breakpoints
  break sum                 Set breakpoint at the entry to function sum
  break *0x80483c3          Set breakpoint at address 0x80483c3
                            (gdb numbers each breakpoint you create)
  delete 1                  Delete  breakpoint 1
  disable 1                 Disable breakpoint 1
  enable 1                  Enable  breakpoint 1
  delete                    Delete all breakpoints
  clear sum                 Clear breakpoints at entry to function sum


Execute
  stepi                     Execute one instruction
  stepi 4                   Execute four instructions
  nexti                     Execute one instruction treating entire
                            function call as one instruction
  step                      Execute one C statement
  continue                  Execute until next breakpoint
  until 3                   Execute until breakpoint 3
  finish                    Execute until current function returns
  call sum(1, 2)            Call sum(1,2) and print return value


Context
  backtrace                 Print the current address and stack backtrace
  where                     Print the current address and stack backtrace
  info program              Print current status of the program)
  info functions            Print functions in program
  info stack                Print backtrace of the stack)
  info frame                Print information about current stack frame
  info registers            Print registers and their contents
  info breakpoints          Print status of user-settable breakpoints







Examine Code
  disas                     Disassemble current function
  disas sum                 Disassemble function sum
  disas 0x80483b7           Disassemble function around 0x80483b7
  disas 0x80483b7 0x80483c7 Disassemble code within specified address range
  print /x $eip             Print program counter in hex
  print /d $eip             Print program counter in decimal
  print /t $eip             Print program counter in binary


Examine Data
  print /d $eax             Print contents of %eax in decimal
  print /x $eax             Print contents of %eax in hex
  print /t $eax             Print contents of %eax in binary
  print 0x100               Print decimal representation of 0x100
  print /x 555              Print hex representation of 555
  print /x ($esp+8)         Print (contents of %esp) + 8 in hex
  print *(int *) 0xbffff890 Print integer at address 0xbffff890
  print *(int *) ($esp+8)   Print integer at address %esp + 8
  print (char *) 0xbfff890  Print string  at address 0xbffff890

  x/w 0xbffff890    Examine 4-byte word starting at address 0xbffff890
  x/w $esp          Examine 4-byte word starting at address in $esp
  x/wd $esp         Examine 4-byte word starting at address in $esp
                    in decimal
  x/2w $esp         Examine two 4-byte words starting at address in $esp
  x/2wd $esp        Examine two 4-byte words starting at address in $esp
                    in decimal
  x/g $esp          Examine 8-byte word starting at address in $esp.
  x/gd $esp         Examine 8-byte word starting at address in $esp
                    in decimal
  x/a $esp          Examine address in $esp
                    as offset from previous global symbol
  x/s 0xbffff890    Examine string stored at 0xbffff890
  x/20b sum         Examine first 20 opcode bytes of function sum
  x/10i sum         Examine first 10 instructions of function sum
  display /FMT EXPR Print expression EXPR using format FMT each time
                    execution stops

Formats: x/[NUM][SIZE][FORMAT]
  If not given, uses sensible default or last-used explicit format
     NUM = number of objects to display
    SIZE = size of each object
           b = byte
           h = half-word
           w = word
           g = giant (quad-word)
  FORMAT = format for displaying each object
           d = decimal
           x = hex
           o = octal