lsxkugoug / os

os

ics-pa is computer system project, which is a simulator to run some small game. Actually, it is a tiny os.This is the course link https://nju-projectn.github.io/ics-pa-gitbook/ics2020/.

os's Issues

my_pstree.c可能的问题

挂掉的原因可能这几个：

void recur(char* filename){ 
     //这个地方要做传入参数判断，保证传入的参数不能为空，否则opendir会挂                                                                                                         
    DIR *dir = opendir(filename);                                                                                                                         
    printf("%s",filename);
    //这个地方如果dir为空，就不能继续下面对步骤，此处应该直接返回                                                                                                                                
    if(dir == NULL) fprintf(stderr,"can not open %s",filename);                                                                                           
    struct  dirent* dptr = NULL;                                                                                                                          
    while(NULL!= (dptr = readdir(dir))){                                                                                                                  
        if(isnumber(dptr->d_name)){                                                                                                                       
            printf("%s\n","|");                                                                                                                           
            printf("%s","-");                                                                                                                             
            printf("%s\n",dptr->d_name);
             //这个地方有风向，因为用的递归，每次调用都需要申请100字节的栈空间，如果目录非常深，就会把栈吃光                                                                                                                    
            char name[100] = "./";
             //task追加到 dptr->d_name后面，无法保证dptr->d_name有足够的空间容纳/task，
             //空间不足会导致越界，直接挂
            strcat(name,strcat(dptr->d_name,"/task"));                                                                         
            recur(name);                                                                                                                                  
        }                                                                                                                                                 
    }                                                                                                                                                     
    closedir(dir);                                                                                                                                        
} 

断是否是数字的方法还可以优化下，只要判断当前字符是‘0’ <= x <= ‘9' 就可以了或者直接使用isdigit