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

CH05.fm Page 159 Monday, October 7, 2002 9:00 PM
Adding Break Points 159
5.6.2 Disabling Break Points
Break points can be disabled temporarily. You can disable a break point using the disable
command with a number as its argument. These numbers can be displayed using the
info break command. The following command lists currently available break points. As you
can see under the Enb column heading, all lines contain a y which shows that all break points
are currently enabled.
(gdb) info break
Num Type Disp Enb Address What
1 breakpoint keep y 0x08048496 in main at sum.c:6
breakpoint already hit 1 time
2 breakpoint keep y 0x080484ba in main at sum.c:8
3 breakpoint keep y 0x080484ca in main at sum.c:9
6 breakpoint keep y 0x08048496 in main at sum.c:5
To disable break point number 3 at line number 9 in file sum.c and then display the status
of break points again, use the following two commands:
(gdb) dis 3
(gdb) info break
Num Type Disp Enb Address What
1 breakpoint keep y 0x08048496 in main at sum.c:6
breakpoint already hit 1 time
2 breakpoint keep y 0x080484ba in main at sum.c:8
3 breakpoint keep n 0x080484ca in main at sum.c:9
6 breakpoint keep y 0x08048496 in main at sum.c:5
(gdb)
Note that you can disable all break points in a single step if you don’t mention any number
as an argument to the disable command.
5.6.3 Enabling Break Points
You can enable previously disabled break points using the enable command. The following
command shows that breakpoint at line number 9 is currently disabled because it shows
an n under the Enb column.
(gdb) info break
Num Type Disp Enb Address What
1 breakpoint keep y 0x08048496 in main at sum.c:6
breakpoint already hit 1 time
2 breakpoint keep y 0x080484ba in main at sum.c:8
3 breakpoint keep n 0x080484ca in main at sum.c:9
6 breakpoint keep y 0x08048496 in main at sum.c:5
The following two commands enable the break point number 3 and display the status of all
break points.