Disassemble a function disassemble vuln
Disassemble at address disassemble 0x400566

display
set disassembly-flavor intel

functions
to display all the functions info func

flags

To view the flags, use the command below:

info reg eflags

breaks
break at function break func

stack 
Display stack stack
view 30 rows of stack stack 30

source

https://cheatography.com/superkojiman/cheat-sheets/gdb-pwndbg/