gdb大全.doc

gdb符号调试器――摘自《Linux上的C编程》
gdb filename
gdb命令祥解
关于断点的命令
awatch
(gdb) l
1 #include<>
2 main()
3 {
4 int i,j;
5 j=0;
6 for (i=0;i<10;i++)
7 {
8 j+=5;
9 printf("now a==%d\n",j);
10 }
(gdb) break 6
Note: breakpoints 1 and 2 also set at pc 0x23dc.
Breakpoint 3 at 0x23dc: file , line 6.
(gdb) run
Starting program: /app/stlm/jacky/test/gdb/lx
Breakpoint 1, main () at :6
for (i=0;i<10;i++)
(gdb) awatch j
(gdb) cont
Continuing.
now a==5
now a==10
now a==15
now a==20
now a==25
now a==30
now a==35
now a==40
now a==45
now a==50
Program exited with code 012.
(gdb)
break
break 行号
or:
break 函数名
clear
清除断点
(gdb) b 6
Note: breakpoints 1, 2 and 3 also set at pc 0x23dc.
Breakpoint 4 at 0x23dc: file , line 6.
(gdb) clear 6
Deleted breakpoints 4 3 2 1
(gdb)
commands
commands 断点号
condition
condition 断点编号(N) 条件表达式
delete
清除断点或自动显示的表达式的值
(gdb) delete 1(断点的编号或者表达式)
(gdb) break 9
Breakpoint 6 at 0x23f4: file , line 9.
(gdb) delete 1
No breakpoint number 1.
(gdb) delete 6
disable
disable 断点编号
enable
enable 断点编号
innore
tbreak
watch
(gdb)watch 要设置观察点的表达式
(gdb) l
1 #include<>
2 main()
3 {
4 int i,j;
5 j=0;
6 for (i=0;i<10;i++)
7 {
8 j+=5;
9 printf("now a==%d\n",j);
10 }
(gdb) b 5
Breakpoint 1 at 0x23d8: file , line 5.
(gdb) run
Starting program: /app/stlm/jacky/test/gdb/lx
Breakpoint 1, main () at :5
5 j=0;
(gdb) watch j
Watchpoint 2: j
(gdb) cont
Continuing.
Watchpoint 2: j
Old value = 0
New value = 5
main () at :9
9 printf("now a==%d\n",j);
(gdb) cont
Continuing.
Watchpoint 2 deleted because the program has left the block in
which its expression is valid.
now a==5
now a==10
now a==15
now a==20
now a==25
now a==30
now a==35
now a==40
now a==45
now a==50
关于数据的命令
display
显示一些表达式的值,使用了该命令之后,每当程序运行到断点处都会显示该表达式的值。
(gdb)display 要显示值的表达式
(gdb) b 9
Breakpoint 1 at 0x23f4: file , line 9.
(gdb) run
Starting program: /app/stlm/jacky/test/gdb/lx