Showing the directory sturcture

This is a discussion on Showing the directory sturcture within the C Programming forums, part of the General Programming Boards category; Hey, I really hope someone on here can help me. I've been working on a program all day, but I ...

  1. #1
    Unregistered
    Guest

    Question Showing the directory sturcture

    Hey,

    I really hope someone on here can help me.
    I've been working on a program all day,
    but I can't seem to get opendir(), readdir() and closedir() to do much.

    Can anybody xplain to me how to get readdir()
    to print the directories in a specified directory on the screen?
    (in Linux)

    UsulB

  2. #2
    Registered User
    Join Date
    Mar 2002
    Posts
    87
    Hi, have a look at the following code this should give you a very grounding on directory related stuff. Scandir is fairly similar to readdir except you can sort it aswell.

    Code:
    #include <stdio.h>
    #include <sys/types.h>
    #include <fcntl.h>
    #include <dirent.h>
    #include <stdlib.h>
    #include <time.h>
    #include <errno.h>
    #include <string.h>
    #include <sys/stat.h>
    #include <pwd.h>
    #include <grp.h>
    #include <unistd.h>
    
    /*prototypes*/
    char* workdir(void);
    void printDetails(char* filename,char* path);
    
    int main(int argc, char **argv) {
      int count,index;
      char *curdir;
      struct stat sbuf;
      struct dirent **direntp;
    
      if(argv[1] != '\0'){
        if(stat(argv[1], &sbuf) != -1){
          if(S_ISDIR(sbuf.st_mode)){ /* Is a directory */
            count = scandir(argv[1],&direntp,NULL,alphasort);
            if(count){
              char path[FILENAME_MAX];
              for(index=0; index<count; ++index){
                strcpy(path,argv[1]);
                printDetails(direntp[index]->d_name,path);
                free(direntp[index]);
              }
            }else{
              fprintf(stderr,"Can't open %s\n",argv[1]);
              exit(EXIT_FAILURE);
            }
          }else
            printDetails(argv[1],NULL);             
        }else
          fprintf(stderr,"Can't stat %s\n", argv[1]);
      }else{
        curdir = workdir(); 
        printf("%s\n",curdir);
        if(stat(curdir,&sbuf) !=-1){
          count = scandir(curdir,&direntp,NULL,alphasort);
          if(count){
            for(index=0; index<count; ++index){
              printDetails(direntp[index]->d_name,NULL);
              free(direntp[index]);
            }
          }else{
            fprintf(stderr,"Can't open %s\n",curdir);
            exit(EXIT_FAILURE);
          }
        }else{
          fprintf(stderr,"Can't stat %s\n",curdir);
          exit(EXIT_FAILURE);
        }
        free(curdir);
      }
      return EXIT_SUCCESS;
    }
    
    char* workdir(){
      while(1){
        char* wdbuf = (char*)malloc(FILENAME_MAX);
        if(getcwd(wdbuf,FILENAME_MAX) == wdbuf)
          return wdbuf;
        free(wdbuf);
        if(errno != ERANGE){
          fprintf(stderr,"Out of range\n");
          return 0;
        }
      }
    }
    
    void printDetails(char *filename,char *path){
    
      struct passwd *my_passwd;	/*User details*/
      struct group *my_group;	/*Group details*/
      struct stat sbuf;		/*File details*/
      struct tm *strtime;		/*Time format*/
    
      int fdes;			/*File descriptor*/
      unsigned char type ='?';	/*File type*/
      unsigned char usr[] = "---";  /*User Permissions*/
      unsigned char grp[] = "---";  /*Group Permissions*/
      unsigned char oth[] = "---";	/*Other Permissions*/
      unsigned char uid[9], gid[9]; /*User name and Group name*/
      unsigned char mod[13];	/*Time information*/
      mode_t mode;			/*Used to determine type and permission bits*/
      char* curdir;			/*Used to hold the current working directory*/
      char* buf;                    /*Used to hold a link location*/
      time_t now;			/*Used to format the time*/
      int year;			/*Used to format the time*/
    
      /*If path is null stat by the curdir*/
      if(path == NULL){
        curdir = workdir();
        strcat(curdir,"/");
        strcat(curdir,filename);
        if(stat(curdir,&sbuf) != -1){
          if(S_ISLNK(sbuf.st_mode)){
            if(readlink(curdir,buf,(size_t)FILENAME_MAX) != -1){
              if(lstat(buf,&sbuf) == -1){
                fprintf(stderr,"Can't stat %s\n",filename);
                return;
              }
            }else
              fprintf(stderr,"Can't readlink %s\n",filename);
          }else if(S_ISREG(sbuf.st_mode)){
            if((fdes = open(curdir,O_RDONLY)) != ENOENT){
              if(fstat(fdes,&sbuf) == -1){
                fprintf(stderr,"Can't stat %s\n",filename);
                return;
              }
              close(fdes);
            }else{
              fprintf(stderr,"Can't open %s\n",filename);
              return;
            }
          }
        }else{
          fprintf(stderr,"Can't stat %s\n",filename);
          return;
        }
        free(curdir);
      /*Otherwise stat by the path provided*/
      }else{
        strcat(path,"/");
        strcat(path,filename);
        if(stat(path,&sbuf) != -1){
          if(S_ISLNK(sbuf.st_mode)){
            if(readlink(path,buf,(size_t)FILENAME_MAX) != -1){
              if(lstat(buf,&sbuf) == -1){
                fprintf(stderr,"Can't stat %s\n",filename);
                return;
              }
            }else
              fprintf(stderr,"Can't readlink %s\n",filename);
          }else if(S_ISREG(sbuf.st_mode)){
            if((fdes = open(path,O_RDONLY)) != ENOENT){
              if(fstat(fdes,&sbuf) == -1){
                fprintf(stderr,"Can't stat %s\n",filename);
                return;
              }
              close(fdes);
            }else{
              fprintf(stderr,"Can't open %s\n",filename);
              return;
            }
          }    
        }else{
          fprintf(stderr,"Path: %s\n",path);
          fprintf(stderr,"Can't stat %s\n",curdir);
          return;
        }
      }      
    
      /*Get file types and permissions*/
      mode = sbuf.st_mode;
      if( S_ISLNK( mode ) ){ type = 'l'; /*symlink*/ printf("%c\n",type);}
      else if( S_ISDIR ( mode ) ) type = 'd'; /*directory*/
      else if( S_ISCHR ( mode ) ) type = 'c'; /*character raw device*/
      else if( S_ISBLK ( mode ) ) type = 'b'; /*block raw device*/
      else if( S_ISFIFO( mode ) ) type = 'p'; /*named pipe*/
      else if( S_ISSOCK( mode ) ) type = 's'; /*Unix domain socket*/
      else if( S_ISREG ( mode ) ) type = '-'; /*regular file*/
      if( mode & S_IRUSR ) usr[0] = 'r';
      if( mode & S_IWUSR ) usr[1] = 'w';
      if( mode & S_IXUSR ) usr[2] = 'x';
      if( mode & S_ISUID ) usr[2] = 's'; /* set UID bit*/
      if( mode & S_IRGRP ) grp[0] = 'r';
      if( mode & S_IWGRP ) grp[1] = 'w';
      if( mode & S_IXGRP ) grp[2] = 'x';
      if( mode & S_ISGID ) grp[2] = 's'; /* set GID bit*/
      if( mode & S_IROTH ) oth[0] = 'r';
      if( mode & S_IWOTH ) oth[1] = 'w';
      if( mode & S_IXOTH ) oth[2] = 'x';
    
      /*Get user information*/
      my_passwd = getpwuid(sbuf.st_uid);
      if(my_passwd != NULL){
        strncpy(uid,my_passwd->pw_name,8);
        uid[8] = '\0';
      }else
        snprintf(uid,9,"%d",sbuf.st_uid);
    
      /*Get group information*/
      my_group = getgrgid(sbuf.st_gid);
      if(my_group != NULL){
        strncpy(gid,my_group->gr_name,8);
        gid[8] = '\0';
      }else
        snprintf(gid,9,"%d",sbuf.st_gid);
    
      /*Format the time to readable form*/
      time(&now);
      year = localtime(&now)->tm_year;
      strtime = localtime(&sbuf.st_ctime);
      if(strtime->tm_year == year)
        strftime(mod,13,"%b %e %R",strtime);
      else
        strftime(mod,13,"%b %e %Y",strtime);
             
      /*print the details*/
      printf("%c%s%s%s    %d %s     %s         %d\t%s %s\n",
             type,usr,grp,oth,sbuf.st_nlink,
             uid,gid,sbuf.st_size,mod,filename);
    
    }
    PuterPaul.co.uk - Portfolio site

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