如何自己实现程序查看文件的读写权限flf1234567898的博客-

利用stat函数实现

int stat(const char *path, struct stat *buf) 

我们来看程序

      8 #define N_BITS 3     9     10 int main(int argc,char *argv[])    11 {    12   unsigned int i,mask = 0700;    13   struct stat buff; W> 14   static char *perm[] = {"---","--x","-w-","-wx","r--","r-x","rw-","rwx"};    15   if(argc>1)    16   {    17     if((stat(argv[1],&buff)!=-1))    18     {    19       printf("permissions for %st",argv[1]);    20       for(i = 3;i;--i)                                                                                      21       {                                                 22         printf("%3s",perm[(buff.st_mode&mask)>>(i-1)*N_BITS]);    23         mask>>=N_BITS;    24       }                                           25       putchar('n');                  26     }                        27     else{                                 28       perror(argv[1]);    29       exit(EXIT_FAILURE);    30                                                                      31     }                                                              32   }                                                         33   else{                                                                                                                                                                                      34     fprintf(stderr,"Usage:%s file_namen",argv[0]);         35   }                                             36                                                                                                                                     37 return 0;               38 } 

测试程序

运行程序

可以看到实现效果相同。