Basic GDB commands

(gdb) l
1       #include <iostream>
2       #include <vector>
3       #include <string>
4
5       using namespace std;
6
7       main()
8       {
9          vector<int> II;
10
(gdb) l
11         II.push_back(10);
12         II.push_back(20);
13         II.push_back(30);
14
15         cout << II.size() << endl;
16
17      }
(gdb) break 15
Breakpoint 1 at 0x8048848: file STL_vector_int.cpp, line 15.
(gdb) r
Starting program: /home/userx/a.out

Breakpoint 1, main () at STL_vector_int.cpp:15
15         cout << II.size() << endl;
(gdb) p II
$1 = {
<std::_Vector_base<int,std::allocator<int> >> = {
_M_impl = {
<std::allocator<int>> = {
<__gnu_cxx::new_allocator<int>> = {<No data fields>}, <No data fields>},
members of std::_Vector_base<int,std::allocator<int> >::_Vector_impl:
_M_start = 0x804b028,
_M_finish = 0x804b034,
_M_end_of_storage = 0x804b038
}
}, <No data fields>}
(gdb) pvector II
elem[0]: $2 = 10
elem[1]: $3 = 20
elem[2]: $4 = 30
Vector size = 3
Vector capacity = 4
Element type = int *
(gdb) c
Continuing.
3

Program exited normally.
(gdb) quit

(gdb) l
1       #include <iostream>
2       #include <vector>
3
4       using namespace std;
5
6       main()
7       {
8          vector< vector<int> > vI2Matrix(3, vector<int>(2,0));
9
10         vI2Matrix[0][0] = 0;
(gdb) l
11         vI2Matrix[0][1] = 1;
12         vI2Matrix[1][0] = 10;
13         vI2Matrix[1][1] = 11;
14         vI2Matrix[2][0] = 20;
15         vI2Matrix[2][1] = 21;
16
17         cout << "Loop by index:" << endl;
18
19         int ii, jj;
20         for(ii=0; ii < 3; ii++)
(gdb) break 17
Breakpoint 1 at 0x8048a19: file STL_vector_2.cpp, line 17.
(gdb) r
Starting program: /home/userx/a.out

Breakpoint 1, main () at STL_vector_2.cpp:17
17         cout << "Loop by index:" << endl;
(gdb) pvector vI2Matrix
elem[0]: $1 = {
<std::_Vector_base<int,std::allocator<int> >> = {
_M_impl = {
<std::allocator<int>> = {
<__gnu_cxx::new_allocator<int>> = {<No data fields>}, <No data fields>},
members of std::_Vector_base<int,std::allocator<int> >::_Vector_impl:
_M_start = 0x804b040,
_M_finish = 0x804b048,
_M_end_of_storage = 0x804b048
}
}, <No data fields>}
elem[1]: $2 = {
<std::_Vector_base<int,std::allocator<int> >> = {
_M_impl = {
<std::allocator<int>> = {
<__gnu_cxx::new_allocator<int>> = {<No data fields>}, <No data fields>},
members of std::_Vector_base<int,std::allocator<int> >::_Vector_impl:
_M_start = 0x804b050,
_M_finish = 0x804b058,
_M_end_of_storage = 0x804b058
}
}, <No data fields>}
elem[2]: $3 = {
<std::_Vector_base<int,std::allocator<int> >> = {
_M_impl = {
<std::allocator<int>> = {
<__gnu_cxx::new_allocator<int>> = {<No data fields>}, <No data fields>},
members of std::_Vector_base<int,std::allocator<int> >::_Vector_impl:
_M_start = 0x804b060,
_M_finish = 0x804b068,
_M_end_of_storage = 0x804b068
---Type <return> to continue, or q <return> to quit---
}
}, <No data fields>}
Vector size = 3
Vector capacity = 3
Element type = class std::vector<int,std::allocator<int> > *
(gdb) pvector $1
elem[0]: $4 = 0
elem[1]: $5 = 1
Vector size = 2
Vector capacity = 2
Element type = int *
(gdb) pvector $2
elem[0]: $6 = 10
elem[1]: $7 = 11
Vector size = 2
Vector capacity = 2
Element type = int *
(gdb) pvector $3
elem[0]: $8 = 20
elem[1]: $9 = 21
Vector size = 2
Vector capacity = 2
Element type = int *
(gdb) p vI2Matrix
$10 = {
<std::_Vector_base<std::vector<int, std::allocator<int> >,std::allocator<std::vector<int, std::allocator<int> > > >> = {
_M_impl = {
<std::allocator<std::vector<int, std::allocator<int> > >> = {
<__gnu_cxx::new_allocator<std::vector<int, std::allocator<int> > >> = {<No data fields>}, <No data fields>},
members of std::_Vector_base<std::vector<int, std::allocator<int> >,std::allocator<std::vector<int, std::allocator<int> > > >::_Vector_impl:
_M_start = 0x804b018,
_M_finish = 0x804b03c,
_M_end_of_storage = 0x804b03c
}
}, <No data fields>}
(gdb) quit