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$ gcc -std=c11 -g -o lab Lab2.c

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GNU gdb (GDB) 7.12.1
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Reading symbols from lab...done.
(gdb)

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(gdb) break printf

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(gdb) break printf
Breakpoint 1 at 0x400540

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(gdb) run
Starting program: /home/alynx/Homework/实验材料（学生版）/实验2/lab
[实验2说明]本练习运行一个三重for循环, 循环结构如下:
int count = 0;
for(int i=0; j<LoopEnd1; i++)
{
	//第一重循环体
	for(int j=0; j<LoopEnd2; j++)
	{
		//第二重循环体
		for(int s=0; s<LoopEnd3; s++)
		{
			count++;//第三重循环体
		}
	}
}
Breakpoint 1, 0x00007ffff7a86e00 in printf () from /usr/lib/libc.so.6

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(gdb) print printf
$1 = {<text variable, no debug info>} 0x7ffff7a86e00 <printf>

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(gdb) bt
#0  0x00007ffff7a86e00 in printf () from /usr/lib/libc.so.6
#1  0x0000000000400745 in main (argc=1, argv=0x7fffffffe078) at Lab2.c:26

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(gdb) step
Single stepping until exit from function printf,
which has no line number information.
main (argc=1, argv=0x7fffffffe078) at Lab2.c:27
27	    scanf("%d", &LoopEnd1);