linux C语言：* glibc detected * ./control: free():invalid pointer:

野性酷女 2023-06-19 04:24 35阅读 0赞

### 前言 ###

**今天遇到了一个问题，折腾好久才找到问题原因，永远不要理想化，各种困难都会浮现的，我们只需要不骄不躁，一定可以解决所有问题。**

### 问题代码 ###

**我们先来看一下问题代码部分吧。**

static char *control_process(char *verb[],char *noun[],char *result)
    { 
    	int verbOpcode = 0; //verb Opcode index
    	int nounOpcode = 0; //noun Opcode index 
        char *Matchverb = (char *)malloc(40*sizeof(char));
    	char *Matchnoun = (char *)malloc(40*sizeof(char));
    	char *Playfile = (char *)malloc(sizeof(char)*40);
    	int index1 = 0;
    	printf("enter the control_process \n\n");
    	for(index1 =1; index1 <37;index1++)
    	{ 	
    		Matchverb = mystrstr1(result,verb[index1]);
    		if(Matchverb != NULL)
    		{ 
    			verbOpcode = index1;
    			break;
    		}else
    		{ 
    			verbOpcode = 0;
    		}
    	}
    	int index2 = 0;
    	for(index2 = 1;index2 <29;index2++)
    	{ 
    		Matchnoun = mystrstr1(result,noun[index2]);
    		if(Matchnoun != NULL)
    		{ 
    			nounOpcode = index2;
    			break;
    		}else
    		{ 
    			nounOpcode=0;
    		}
    	}
    	printf("achieve the verb and noun deal \n\n");
    	sprintf(Playfile,"/mnt/card/1%02d2%02d",verbOpcode,nounOpcode);
    	printf("play file is %s \n\n",Playfile);
    	free(Matchverb);
    	free(Matchnoun);
    	return Playfile;
    	
    }

### 解决问题 ###

**就是这段代码，一直报错，初看确实看不到什么问题，为此我加了很多打印，最后确定问题就发生在 free(Matchverb);free(Matchnoun);这两句话，下面就讲一个一知识点，为什么free发生异常了呢？**  
**我们在使用malloc分配内存后，指针变量获取到了地址。但是在程序中我们又给指针变量重新赋值了，因此地址发生了变化，此时我再次使用free()来释放，已经不是原来malloc分配的内存地址了，因此这就是指针地址非法。**

### 修改方法 ###

**为了防止地址发生变化，我可以在定义两个指针变量保存malloc分配初地址，然后在释放之前将初地址重新赋值回去，这样就完美解决了。**

static char *control_process(char *verb[],char *noun[],char *result)
    { 
    	int verbOpcode = 0; //verb Opcode index
    	int nounOpcode = 0; //noun Opcode index 
        char *Matchverb = (char *)malloc(40*sizeof(char));
    	char *Matchnoun = (char *)malloc(40*sizeof(char));
    	char *Playfile = (char *)malloc(sizeof(char)*40);
    	char *p1 = Matchverb;
    	char *p2 = Matchnoun;
    	int index1 = 0;
    	printf("enter the control_process \n\n");
    	for(index1 =1; index1 <37;index1++)
    	{ 	
    		Matchverb = mystrstr1(result,verb[index1]);
    		if(Matchverb != NULL)
    		{ 
    			verbOpcode = index1;
    			break;
    		}else
    		{ 
    			verbOpcode = 0;
    		}
    	}
    	int index2 = 0;
    	for(index2 = 1;index2 <29;index2++)
    	{ 
    		Matchnoun = mystrstr1(result,noun[index2]);
    		if(Matchnoun != NULL)
    		{ 
    			nounOpcode = index2;
    			break;
    		}else
    		{ 
    			nounOpcode=0;
    		}
    	}
    	printf("achieve the verb and noun deal \n\n");
    	sprintf(Playfile,"/mnt/card/1%02d2%02d",verbOpcode,nounOpcode);
    	printf("play file is %s \n\n",Playfile);
    	Matchverb = p1;
    	Matchnoun = p2;
    	free(Matchverb);
    	free(Matchnoun);
    	return Playfile;
    	
    }

**完美解决问题，这是我想到的办法，如果你有更好的办法，欢迎讨论，互相学习！！！！**