The Linux Development Platform Configuring, Using, and ... - Classes

CH05.fm Page 156 Monday, October 7, 2002 9:00 PM
156 Chapter 5 • Working with GNU Debugger
(gdb) n
Enter second number : 12
14 total = sum(num1, num2);
(gdb) print num1
$1 = 34
(gdb) set num1=11
(gdb) print num1
$2 = 11
(gdb) print num2
$3 = 12
(gdb) n
Calculation complete. Returning ...
15 printf("\nThe sum is : %d\n", total);
(gdb) n
The sum is : 23
16 }
(gdb)
5.6 Adding Break Points
When you start debugging a program, you use the run command. This command executes the
program until the end of the program or a break point is met. A break point is a place in your
source code file where you temporarily want to stop execution of the program being debugged.
Break points in GNU debugger can be placed using the break command. Look at the following
list of the source code file sum.c which you already have used:
(gdb) list
1 #include
2 main ()
3 {
4 int num1, num2, total ;
5
6 printf("Enter first number : ");
7 scanf("%d", &num1);
8 printf("Enter second number : ");
9 scanf("%d", &num2);
10
(gdb)
To place a break point at line number 6 in file sum.c (displayed above), you can use the
following command:
(gdb) break sum.c:6
Breakpoint 1 at 0x8048496: file sum.c, line 6.
(gdb)