radare2 notes

r2.sh

# get only import names
afl~sym.imp[3]

# get only import addrs
afl~sym.imp[0]

# set breakpoint at 0x0 and 0x1
db $$ @@= `!echo -e "0x0\n0x1"`

# set breakpoint at every imported function 
db $$ @@= `afl~sym.imp[0]`

# find all crossreferences of imported methods
axt $$ @@= `afl~sym.imp[0]`
entry0 0x565d614c [CALL] call sym.imp.__libc_start_main
(nofunc) 0x565d631d [CALL] call sym.imp.read
(nofunc) 0x565d643a [CALL] call sym.imp.read
(nofunc) 0x565d63a5 [CALL] call sym.imp.signal
(nofunc) 0x565d63b2 [CALL] call sym.imp.alarm
(nofunc) 0x565d629d [CALL] call sym.imp.perror
(nofunc) 0x565d62d0 [CALL] call sym.imp.perror
(nofunc) 0x565d63f6 [CALL] call sym.imp.strcpy
(nofunc) 0x565d6425 [CALL] call sym.imp.malloc
(nofunc) 0x565d6306 [CALL] call sym.imp.open
(nofunc) 0x565d633d [CALL] call sym.imp.srand
(nofunc) 0x565d63ce [CALL] call sym.imp.mmap
(nofunc) 0x565d640c [CALL] call sym.imp.memset
(nofunc) 0x565d6287 [CALL] call sym.imp.prctl
(nofunc) 0x565d62ba [CALL] call sym.imp.prctl
(nofunc) 0x565d634e [CALL] call sym.imp.rand
(nofunc) 0x565d632b [CALL] call sym.imp.close

# store the addresses of the crossreferences of the import addresses into a file
 axt $$ @@= $(afl~sym.imp[0]) | awk '{ print $2 }' > ./imp_xrefs_addrs.txt
 
# load the crossreferences of the import addresses, iterate over them and set breakpoints
db $$ @@.imp_xrefs_addrs.txt
0x565d614c: db $$
0x565d631d: db $$
0x565d643a: db $$
0x565d63a5: db $$
0x565d63b2: db $$
0x565d629d: db $$
0x565d62d0: db $$
0x565d63f6: db $$
0x565d6425: db $$
0x565d6306: db $$
0x565d633d: db $$
0x565d63ce: db $$
0x565d640c: db $$
0x565d6287: db $$
0x565d62ba: db $$
0x565d634e: db $$
0x565d632b: db $$