1. gcc ... -omain -g
-g : The function and variable names will be saved.
2. start gdb
gdb appName
set args xxx xxx xxx
Pass arguments to the app
3. l command:
l : show source code, and type "enter" to continue show source code.
show listsize : Number of source lines gdb will list by default is 10
set listsize 20: set it 20
l 5 : show line 5
l insert_sort.c:5 : show line 5 of insert_sort.c
l insert_sort.c:func : show the code of a func
l main.c:main : show the code of a func
4. breakpoint operations:
b 14 : set breakpoint in line 14
b 17 : set breakpoint in line 17
i b : show all the breakpoints
d 1 : delete the first breakpoint
d 2 3 : delete two breakpoints at the same time
d 4-7 : delete breakpoints the fourth to seventh
dis 2 : disable the second breakpoint
ena 2 : enable the second breakpoint
r : running
p i : show the value of i
b 17 if i==10 : set condition breakpoint
set the breakpoint and it will be hit when i==10
5. debug operations
r : run app and stop at the first breakpoint
p i : show the value of i
p array[i] : show value of the ith element
ptype i : show the type of i
n : go by one step
display i : display i in every step
i(info) display : show all display
undisplay i(the ith one) : Contrary to the display
step : get into a func
finish : get out of a func,but you must delete all breakpoints in the func.
c(continue) : continue to debug and stop at next breakpoint
5. other operations
q(quit) ： quit gdb
set var i=5 : set the value of i
until : Jump out of the loop,but you must delete all breakpoints in the loop
start : run a line and then stop,used after starting gdb
r : run to the first breakpoint and then stop