gdb cheat-sheet

• Starting and stopping gdb

        gdb
        gdb <file>
        gdb -h             (lists command line options)
        quit
        Ctrl-d
        Note: Ctrl-C does not exit from gdb, but halts the current gdb command

• General commands

        run                (start your program)
        kill               (stop the program)

• Breakpoints

        break FUNCTION     (set a breakpoint at the entry to the function)
        break *ADDRESS     (set a breakpoint at the specified address)
        disable <NUM>      (disable the breakpoint with that number)
        enable <NUM>       (enable the breakpoint with that number)
        clear FUNCTION     (clear any breakpoints at the entry to the function)
        delete <NUM>       (deletes the breakpoint with that number)
        delete             (deletes all breakpoints)

• Working at breakpoints

        stepi              (execute one instruction)
        stepi <NUM>        (execute NUM instructions)
        nexti              (execute one instruction, stepping over functions)
        nexti <NUM>        (execute NUM instructions, stepping over functions)
        until LOCATION     (continue running until LOCATION is reached)
        continue           (resume execution)
        continue <NUM>     (continue, ignoring this breakpoint NUM times)
        finish             (run until the current function returns)
        backtrace          (print the current address and stack backtrace)
        where              (print the current address and stack backtrace)

• Examining code and date

      disas                 (display the function around the current line)
      disas ADDR            (display the function around the address)
      disas ADDR1 ADDR2 (display the function between the addresses)
      print/a $pc           (print  the program counter)
      print $sp             (print  the stack pointer)
      print $eax            (print  the contents of %eax)
      print/x $eax          (print  the contents of %eax as hex)
      print/a $eax          (print  the contents of %eax as an address)
      print/d $eax          (print  the contents of %eax as decimal)
      print/t $eax          (print  the contents of %eax as binary)
      print/c $eax          (print  the contents of %eax as a character)
      print 0×100           (print decimal repr. of hex value)
      print/x 555           (print hex repr. of decimal value)
      x ADDR                (print the contents of ADDR in memory)
      x/NFU ADDR            (print the contents at ADDR in memory:
                                 N = number of units to display
                                 F = display format
                                 U = b (bytes), h (2 bytes), w (4 bytes))
      x/10i ADDR            (print the next 10 instructions)

• Autodisplaying information

      display $eax          (print contents of %eax every time the
                                 program stops)
      display               (print the auto-displayed items)
      delete display <NUM>         (stop displaying item NUM)

Free up space on your Mac OSX HDD

Came across this useful link (also posted on Digg) for freeing up space on Mac OSX HDD. The practical nature of the article really impressed me.

Must-have OSX Applications

I have been using Mac OSX for close to an year now and I have been very happy that I made the ’switch’. I have so far found an application for ANYTHING that I would have wanted to do in the Linux+Windows world. This page lists ‘must-have’ freeware which is available for Mac OSX. I selectively use some of the applications listed on the page, partly because I am very particular about what I install on my computers.