調用執行opendir和readdir的是改變了我的字符數組

Question

這是代碼我到目前爲止，找到根源在哪裏是好的，但是當我添加一行：

printf("  name: %s\n", readdir(opendir(cur_spot))->d_name); 

它改變cur_spot，並增加了怪異字符它（文件名：。〜？）是它打印..任何想法，爲什麼發生這種情況？

#include <time.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <dirent.h> 
#include <sys/stat.h> 
#include <sys/types.h> 

int main(int argc, char *argv[]) { 
    struct stat file_stats; 
    struct stat parent_stats; 
    struct dirent temp_dir; 

    char cwd_name[256]; //directory name 
    char cur_spot[256]; //current directory spot 

    cur_spot[0] = '.'; 
    stat(cur_spot, &file_stats); 
    printf("filename: %s\n", cur_spot); 
    printf(" inode: %ld\n", file_stats.st_ino); 


    strcat(cur_spot, "."); 
    stat(cur_spot, &parent_stats); 
    printf("filename: %s\n", cur_spot); 
    printf(" inode: %ld\n", parent_stats.st_ino); 

    while(file_stats.st_ino != parent_stats.st_ino) { 
     printf("not at root yet\n\n"); 

     stat(cur_spot, &file_stats); 
     printf(" current child\n"); 
     printf("  inode: %ld\n", file_stats.st_ino); 
     printf("  name: %s\n", readdir(opendir(cur_spot))->d_name); 
     strcat(cur_spot, "/.."); 
     stat(cur_spot, &parent_stats); 
     printf(" current parent\n"); 
     printf("  inode: %ld\n", parent_stats.st_ino); 
    } 
     printf("at root\n"); 


    return 0; 
} 

Answer 1

這工作得很好，我對GCC：

#include <time.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <dirent.h> 
#include <sys/stat.h> 
#include <sys/types.h> 

int main(int argc, char *argv[]) { 
    struct stat file_stats; 
    struct stat parent_stats; 
    struct dirent temp_dir; 
    DIR *dirp; 

    char cwd_name[256]; //directory name 
    char cur_spot[256]; //current directory spot 

    strcpy(cur_spot,"."); // <------------ changed 
    stat(cur_spot, &file_stats); 
    printf("filename: %s\n", cur_spot); 
    printf(" inode: %ld\n", file_stats.st_ino); 


    strcat(cur_spot, "."); 
    stat(cur_spot, &parent_stats); 
    printf("filename: %s\n", cur_spot); 
    printf(" inode: %ld\n", parent_stats.st_ino); 

    while(file_stats.st_ino != parent_stats.st_ino) { 
     printf("not at root yet\n\n"); 

     stat(cur_spot, &file_stats); 
     printf(" current child\n"); 
     printf("  inode: %ld\n", file_stats.st_ino); 
     dirp=opendir(cur_spot); // <----------------added 
     printf("  name: %s\n", readdir(dirp)->d_name); // <----changed 
     closedir(dirp); // <------------------------added 
     strcat(cur_spot, "/.."); 
     stat(cur_spot, &parent_stats); 
     printf(" current parent\n"); 
     printf("  inode: %ld\n", parent_stats.st_ino); 
    } 
     printf("at root\n"); 


    return 0; 
} 

Answer 2

你應該在一個字符數組的末尾添加一個空字符。

錯誤：

cur_spot[0] = '.'; 

右：

空字符結束的字符串。默認情況下，字符串可以或不可以初始化爲NULL。

Answer 3

你在循環中做了一堆「opendir」，但我看不到「closedir」的痕跡。你應該受到懲罰......

Answer 4

這超出了你最初的問題範圍，所以我把它作爲一個單獨的答案加入我的第一個問題。正如我在我的第一個回答下的評論中所說的那樣，如果您打算在目錄中打印所有文件的文件名，那麼您只需要繼續調用readdir（），直到出現一些終止條件，從讀取手冊頁開始，它只是一個NULL返回值。順便說一句，如果你的手冊頁說READDIR(2)或This is not the function you are interested in，你真正想要做的是看readdir上的第3節手冊頁，你可以用man -s 3 readdir得到。

反正我改裝成的代碼從我的第一個答案做什麼，我想你想：

#include <time.h> 
#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <dirent.h> 
#include <sys/stat.h> 
#include <sys/types.h> 

int main(int argc, char *argv[]) { 
    struct stat file_stats; 
    struct stat parent_stats; 
    struct dirent temp_dir; 
    DIR *dirp; 
    struct dirent* dent; 

    char cwd_name[256]; //directory name 
    char cur_spot[256]; //current directory spot 

    strcpy(cur_spot,".");   // <------------- changed 
    stat(cur_spot, &file_stats); 
    printf("filename: %s\n", cur_spot); 
    printf(" inode: %ld\n", file_stats.st_ino); 


    strcat(cur_spot, "."); 
    stat(cur_spot, &parent_stats); 
    printf("filename: %s\n", cur_spot); 
    printf(" inode: %ld\n", parent_stats.st_ino); 

    while(file_stats.st_ino != parent_stats.st_ino) { 
     printf("not at root yet\n\n"); 

     stat(cur_spot, &file_stats); 
     printf(" current child\n"); 
     printf("  inode: %ld\n", file_stats.st_ino); 
     dirp=opendir(cur_spot); // <------------- added 
     do {      // <------------- NEW 
      dent = readdir(dirp); // <------------- NEW 
      if (dent)    // <------------- NEW 
       printf("  name: %s\n", dent->d_name); 
     } while (dent);   // <------------- NEW 
     closedir(dirp);   // <------------- added 
     strcat(cur_spot, "/.."); 
     stat(cur_spot, &parent_stats); 
     printf(" current parent\n"); 
     printf("  inode: %ld\n", parent_stats.st_ino); 
    } 
     printf("at root\n"); 


    return 0; 
}