GDB cheat sheet

Here is the cheat sheet for GDB in Linux

• Enable the core file

% ulimit -a
% ulimit -c 500000

Set maximum core file size to 500K.

• List all  proc information and function list

(gdb) info proc
(gdb) info functions

• Disasseeble

(gdb) disass main

• Display and clear breakpoints

(gdb) info breakpoints
(gdb) delete breakpoints 1

• Watching it live

(gdb) break 188
(gdb) commands 1
print variable
continue
end

Note: break at 188 lines and then set a group of commands at break point 1.

• Break when a specific address is accessed. Refer to this article.

(gdb)  watch *((int*)0xABCDEF)

• Define in macro and alias in ~/.gdbinit A good article about it.

As an simple example:
define cls
shell clear
end
document cls
clears screen for gdb
end

Example Macros for STL debugging. 

• Handle Signal

(gdb) i handle
(gdb) i signal
(gdb) handle SIG32 nostop print pass

• Multiple threads

(gdb) b foo.cpp:13 thread 28 if x>lim

• Remote debugging

Server side: gdbserver:9999 -attach pid
Client side: gdb program
(gdb) handle SIGTRAP nonstop noprint pass
(gdb) target remote gdbserverip:9999

• Store history

Convenience variables:
(gdb) set $table=*table_ptr
(gdb) show conv

Checkpoint
(gdb) checkpoint
(gdb) i checkpoint
(gdb) restart checkpoint-id

• See Macros in program

g++ -gdwarf-2 -g3 a.cpp

• Why the program is stopped

(gdb) i prog

• exit a loop

(gdb) until line-no

• print, info, show

print: print value of expression
info: show things about the program being debugged
show: show things about the debugger