Directory operations (C language)

Directory operations (C language) header file:

• #include <unistd.h>
• #include <sys/stat.h>
• #include <dirent.h>

Read Directory

Required header files: #include <dirent.h>

• Open the directory and return an empty pointer at the time of the failure.

  DIR * OPENDIR (const char *path)

• Reading a directory Readdir,readdir equivalent to a file operation function Read,dir struct equivalent to a file structure inside a document operation.

  struct Dirent *readdir (DIR *pdir)

  Dirent Structural Body:

  struct dirent  {  long d_ino; /* inode number 索引节点号 */ off_t d_off; /* 在目录文件中的偏移 */ unsigned short d_reclen; /* 文件名长 */ unsigned char d_type; /* 文件类型 */ char d_name [NAME_MAX+1]; /*文件名，最长256字符 */ }

• Close Directory

  int Closedir (DIR *pdir)

To create a directory:

int mkdir (const char *path, mode_t mode)

To delete a directory:

int rmdir (char *path)

Get the current directory absolute path:

• char * GETCWD (char *path, size_t size)

  GETCWD Success returns the current working directory, failure returns FALSE

  Parameters: The absolute path of the current working directory is copied to the memory space referred to in the parameter path, and the parameter size is the space size of path.

Setting path to the current working directory requires X permissions on the directory:

ChDir (char *path)

Set FD corresponding directory as current working directory:

Fchdir (int fd)

Example:

#Include<stdio.h>#Include<string.h>#Include<sys/stat.h>#Include<sys/types.h>#Include<unistd.h>#Include<errno.h>#Include<dirent.h>IntGetfiletype(Char *filepath,Char *type) {if (filepath==NULL) {perror ("The FilePath is not NULL");Return-1;}structStatStbuf;if (stat (FILEPATH,&AMP;STBUF)) {fprintf (StdErr"Fail to stat file[%s]:%s\n", Filepath,strerror (errno));Return-1;}Switch (STBUF.ST_MODE&AMP;S_IFMT) {Case S_ifdir:*type=' d ';BreakCase S_ifreg:*type=‘-‘;BreakDefault:*type=' O ';break;}Return0;}IntTree(Char *filepath,int deep) {DIR *pdir;structDirent *Pdent;Char Type;pdir=opendir (FilePath);int i;Char szsubdir[256];if (pdir==NULL) {fprintf (StdErr"Faie to open:[%s]", FilePath);Return0;}sprintf (Szsubdir,"./%s", FilePath); ChDir (Szsubdir);While1) {Pdent=readdir (pdir);if (pdent==NULL) {break;}Ifstrcmp (Pdent->d_name,".") ==0| |strcmp (Pdent->d_name,"..") ==0) {Continue;}for (i=0;i<deep;i++) {printf ("----");} printf ("%s\n", pdent->d_name); Getfiletype (Pdent->d_name,&type); if (type==' d ') {Tree (pdent->d_name,deep+1);}} ChDir (".. /"); Closedir (Pdir); return 0;} int main() {char szbuf[256];getcwd (szbuf,256); Tree (Szbuf,1);  return 0;}                   

Some other functions about directory operations:

• void Seekdir (DIR *pdir, long int locate)

  Similar to Fseek ()

• void Rewinddir (DIR *pdir)

  Similar to Rewind ()

• Long int telldir (DIR *pdir)

  Similar to Ftell ()

Directory operations (C language)