EECS 280

gdb Command Summary



1. Compiling


To use gdb, you will need to first compile your program using the g++ with the –g flag.

% g++ -g projX.cpp –o projX.exe


2. Running gdb / Command line options


% gdb projX.exe

      Starts gdb and loads the projX.exe executable into the debugger.


% gdb –help

      Lists all the options with a brief summary for each


% gdb projX.exe –core=<core file>

      Starts gdb, loads the projX.exe executable and processes core file information.  Useful if your program has a segmentation fault.


3. gdb Commands


help (h)

Brings up the help options.

run (r)

(Re)starts running your program.  Can add command line optionsyou’re your program here.

quit (q)

Stop running your program and quits gdb.


break (b)

Set a breakpoint at current position.

break <function>

Break at specified function in current file.

break <file>:<function>

Break at function in specified file.

break <line num>

Break at line number in current file.

break <file>:<line num>

Break at line number in specified file.

delete (d)

Remove lowest breakpoint number.

delete <breakpoint num>

Delete specified breakpoint.

info breakpoints

List all the breakpoints and their numbers.


continue (c)

Continue executing.

next (n)

Executes next line (does not enter functions).

until (u)

Executes until end of current loop structure.

step (s)

Executes next line (enters functions).


list (l)

Shows code surrounding current line number.

list <function>

Show code at start of specified function.

list <line num>

Show code surrounding specified line number.


print <expression>

Show value of the expression.

print <array var>@<num>

Show first num values in the specified array.

display <expression>

Like print, but expression is shown at every “step” through the program.

undisplay <display num>

Stop displaying the specified display expression.


4. More information


% man gdb



Adapted from the GNU gdb manual page.


     Last Update: D. Emerson 9/7/2002 10:36:15 AM