gdb Command

ctrl+x+a      // -tui mode
gdb -d  | set directory  // set src  directory
show directories

set logging on
set logging file file.log
set logging overwrite [on|off]
set logging redirect [on|off]
set logging


gdb tty /dev/pts/8

run arg0 arg1 ...
set args arg0 arg1 ...
show args
file program

finish        //执行到函数返回 gu
c             //继续执行  g
until         //执行到某处
print *ptr    //
print *ptr@10 //显示数组中的10个元素
display *ptr  //自动显示

watch x       //x 变化时中断

break file.c:function if <COND> | info breakpoints | clear | delete | disable | enable
tbreak  args  //中断一次
hbreak  args //硬件断点
thbreak args  //中断一次硬件断点

rbreak  regex //在所有匹配 regex表达式的函数上设断
rbreak .    //程序所有函数


backtrace | bt  // k

frame
comands
disassemble

layout asm
disas main
x/10i main
info reg
si
ni

Command	Description
help	List gdb command topics.
help topic-classes	List gdb command within class.
help command	Command description.
apropos search-word	Search for commands and command topics containing search-word.
info args i args	List program command line arguments
info breakpoints	List breakpoints
info break	List breakpoint numbers.
info break breakpoint-number	List info about specific breakpoint.
info watchpoints	List breakpoints
info registers	List registers in use
info threads	List threads in use
info set	List set-able option
Break and Watch
break funtion-name break line-number break ClassName::functionName	Suspend program at specified function of line number.
break +offset break -offset	Set a breakpoint specified number of lines forward or back from the position at which execution stopped.
break filename:function	Don't specify path, just the file name and function name.
break filename:line-number	Don't specify path, just the file name and line number. break Directory/Path/filename.cpp:62
break *address	Suspend processing at an instruction address. Used when you do not have source.
break line-number if condition	Where condition is an expression. i.e. x > 5 Suspend when boolean expression is true.
break line thread thread-number	Break in thread at specified line number. Use info threads to display thread numbers.
tbreak	Temporary break. Break once only. Break is then removed. See "break" above for options.
watch condition	Suspend processing when condition is met. i.e. x > 5
clear clear function clear line-number	Delete breakpoints as identified by command option.
delete d	Delete all breakpoints, watchpoints, or catchpoints.
delete breakpoint-number delete range	Delete the breakpoints, watchpoints, or catchpoints of the breakpoint ranges specified as arguments.
disable breakpoint-number-or-range enable breakpoint-number-or-range	Does not delete breakpoints. Just enables/disables them. Example: Show breakpoints: info break Disable: disable 2-9
enable breakpoint-number once	Enables once
continue c	Continue executing until next break point/watchpoint.
continue number	Continue but ignore current breakpoint number times. Usefull for breakpoints within a loop.
finish	Continue to end of function.
Line Execution
step s step number-of-steps-to-perform	Step to next line of code. Will step into a function.
next n next number	Execute next line of code. Will not enter functions.
until until line-number	Continue processing until you reach a specified line number. Also: function name, address, filename:function or filename:line-number.
info signals info handle handle SIGNAL-NAME option	Perform the following option when signal recieved: nostop, stop, print, noprint, pass/noignore or nopass/ignore
where	Shows current line number and which function you are in.
Stack
backtrace bt bt inner-function-nesting-depth bt -outer-function-nesting-depth	Show trace of where you are currently. Which functions you are in. Prints stack backtrace.
backtrace full	Print values of local variables.
frame frame number f number	Show current stack frame (function where you are stopped) Select frame number. (can also user up/down to navigate frames)
up down up number down number	Move up a single frame (element in the call stack) Move down a single frame Move up/down the specified number of frames in the stack.
info frame	List address, language, address of arguments/local variables and which registers were saved in frame.
info args info locals info catch	Info arguments of selected frame, local variables and exception handlers.
Source Code
list l list line-number list function list - list start#,end# list filename:function	List source code.
set listsize count show listsize	Number of lines listed when list command given.
directory directory-name dir directory-name show directories	Add specified directory to front of source code path.
directory	Clear sourcepath when nothing specified.
Machine Language
info line info line number	Displays the start and end position in object code for the current line in source. Display position in object code for a specified line in source.
disassemble 0xstart 0xend	Displays machine code for positions in object code specified (can use start and end hex memory values given by the info linecommand.
stepi si nexti ni	step/next assembly/processor instruction.
x 0xaddress x/nfu 0xaddress	Examine the contents of memory. Examine the contents of memory and specify formatting. n: number of display items to print f: specify the format for the output u: specify the size of the data unit (eg. byte, word, ...) Example: x/4dw var
Examine Variables
print variable-name p variable-name p file-name::variable-name p 'file-name'::variable-name	Print value stored in variable.
p *array-variable@length	Print first # values of array specified by length. Good for pointers to dynamicaly allocated memory.
p/x variable	Print as integer variable in hex.
p/d variable	Print variable as a signed integer.
p/u variable	Print variable as a un-signed integer.
p/o variable	Print variable as a octal.
p/t variable x/b address x/b &variable	Print as integer value in binary. (1 byte/8bits)
p/c variable	Print integer as character.
p/f variable	Print variable as floating point number.
p/a variable	Print as a hex address.
x/w address x/4b &variable	Print binary representation of 4 bytes (1 32 bit word) of memory pointed to by address.
GDB Modes
set gdb-option value	Set a GDB option
set logging on set logging off show logging set logging file log-file	Turn on/off logging. Default name of file is gdb.txt
set print array on set print array off show print array	Default is off. Convient readable format for arrays turned on/off.
set print array-indexes on set print array-indexes off show print array-indexes	Default off. Print index of array elements.
set print pretty on set print pretty off show print pretty	Format printing of C structures.
set print union on set print union off show print union	Default is on. Print C unions.
set print demangle on set print demangle off show print demangle	Default on. Controls printing of C++ names.
Start and Stop
run r run command-line-arguments run < infile > outfile	Start program execution from the beginning of the program. The command break main will get you started. Also allows basic I/O redirection.
continue c	Continue execution to next break point.
kill	Stop program execution.
quit q	Exit GDB debugger.