This is extention for gdb in Linux.
You can input any bytes via stdin.
add follwing line to .gdbinit
source <path_to_gdbinit_hexinput.py>
(gdb)start
(gdb)hexinput 11223344
(gdb-peda)start
(gdb-peda)hexinput 0x11223344
you can pack with nbytes
(gdb)start
(gdb)hexinput 0xdeadbeef 8 #0xdeadbeef will be packed for 8bytes little endian