start command
Sets a temporary breakpoint on main() and starts executing a program under GDB.
Syntax
start [Arguments]
Parameters
- Arguments
- Specifies the command-line arguments passed to the program via argv and argc parameters.
Restrictions
The start command should only be used if you want to debug a new instance of the program. Use the continue command instead in the following cases:
- To resume a process after attaching to it with attach
- To start debugging with gdbserver
- To continue from a breakpoint
If you issue the start command after a breakpoint is hit, your program will be restarted from the beginning.
Remarks
For C/C++ programs the start command is equivalent to the following command sequence:
run
Examples
The following commands start executing a program passing "Hello World" as arguments:
Temporary breakpoint 1 at 0x80483b7: file 0.cpp, line 3.
Starting program: /home/testuser/0.elf "Hello World"
Temporary breakpoint 1, main (argc=2, argv=0xbffff774) at 0.cpp:33 return 0;
(gdb) print *argv@argc
$1 = {0xbffff895 "/home/testuser/0.elf", 0xbffff8aa "Hello World"}
This example shows that the start command issued after attaching to a process will restart it:
Attaching to program: /home/testuser/0.elf, process 28325
Reading symbols from /lib/i386-linux-gnu/libc.so.6...
done.
Loaded symbols for /lib/i386-linux-gnu/libc.so.6
0xb7768424 in __kernel_vsyscall ()
(gdb) start
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Temporary breakpoint 1 at 0x8048444: file 0.cpp, line 3.
Starting program: /home/testuser/0.elf
Temporary breakpoint 1, main (argc=1, argv=0xbffff844) at 0.cpp:3
3 {
Common errors
Using the start command to start debugging with gdbserver will result in an error. Use the continue command instead:
Remote debugging using :2001
Reading symbols from /lib/ld-linux.so.2...Reading symbols from /usr/lib/debug/lib/i386-linux-gnu/ld-2.15.so...done.
done.
Loaded symbols for /lib/ld-linux.so.2
0xb7fdf1d0 in _start () from /lib/ld-linux.so.2
(gdb) start
The "remote" target does not support "run". Try "help target" or "continue".
(gdb) b main
Breakpoint 1 at 0x8048444: file 0.cpp, line 3.
(gdb) continue
Continuing.
Breakpoint 1, main (argc=1, argv=0xbffff7a4) at 0.cpp:3
3 {
Compatibility with VisualGDB
Do not execute the start command manually under Visual Studio. VisualGDB automatically issues an equivalent of the run command when you press F5 to start your debugging session:
