//make it work
/* ls2.c
* purpose list contents of directory or directories
opens directories recursively and displays contents
need to display link???
and an option -s...only display the directories
probable error in dynamic memory allocation or related
*/

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

int flag=0; //for option s

void do_ls(char[]);
void dostat(char *);
void show_file_info( char *, struct stat *);
void mode_to_letters( int , char [] );
char *uid_to_name( uid_t );
char *gid_to_name( gid_t );
void insert( struct NODE *, struct NODE *);
void inorder(struct NODE *);
void printfile(struct NODE *);

main(int ac, char *av[])
{ char ch;
  
  while ((ch=getopt(ac, av, "s")) != -1) {
      if(ch=='s') flag=1;
      
      if ( ac == 1 )
          do_ls( "." );
      else
          while ( --ac ){
              printf("%s:\n", *++av );
              do_ls( *av );
          }
  }
  
  void do_ls( char dirname[] )
  /*
   * list files in directory called dirname
   */
  {
      DIR *dir_ptr; /* the directory */
      struct dirent *direntp; /* each entry */
      
      if ( ( dir_ptr = opendir( dirname ) ) == NULL )
          fprintf(stderr, "ls1: cannot open %s\n", dirname);
      else {
          while ( ( direntp = readdir( dir_ptr ) ) != NULL )
              dostat( direntp->d_name );
          closedir(dir_ptr);
      }
  }
  
  void dostat( char *filename ) {
      struct stat info;
      
      if ( stat(filename, &info) == -1 ) /* cannot stat */
          perror( filename ); /* say why */
      else /* else show info */
          show_file_info( filename, &info );
  }
  
  void show_file_info( char *filename, struct stat *info_p )
  /*
   * display the info about 'filename'. The info is stored in struct at *info_p
   */
  {
      char *uid_to_name(), *ctime(), *gid_to_name(), *filemode();
      void mode_to_letters();
      char modestr[11];
      
      mode_to_letters( info_p->st_mode, modestr );
      
      
      //if(modestr[0]=='d'){
      //struct NODE *root;
      //}
      
      
      struct NODE *new;
      new=((struct NODE*)malloc(sizeof(struct NODE)));
      new->depth=0;
      new->fname=filename;
      new->dirtree=NULL;
      
      new->dflag=0;
      new->eflag=0;
      if(modestr[0]!='d' && (modestr[3]=='x' || modestr[6]=='x' || modestr[9]=='x')) new->eflag=1;//file is an executable
      
      switch(modestr[0]) {
          case 'd':
              new->value=1;
              new->dflag=1;
              do_ls(filename);
              
              //isdir(new);
              break;
              
          case 'c':
              new->value=2;
              break;
              
          case 'b':
              new->value=3;
              break;
              
          case 'l':
              new->value=4;
              break;
              
          default:break;
      }
      
      insert(root, new);
      
      
      //printf( "%s" , modestr );
      //printf( "%4d " , (int) info_p->st_nlink);
      //printf( "%-8s " , uid_to_name(info_p->st_uid) );
      //printf( "%-8s " , gid_to_name(info_p->st_gid) );
      //printf( "%8ld " , (long)info_p->st_size);
      //printf( "%.12s ", 4+ctime(&info_p->st_mtime));
      //printf( "%s\n" , filename );
      
  }
  
  /*
   * utility functions
   */
  
  /*
   * This function takes a mode value and a char array
   * and puts into the char array the file type and the
   * nine letters that correspond to the bits in mode.
   * NOTE: It does not code setuid, setgid, and sticky
   * codes
   */
  void mode_to_letters( int mode, char str[] ) {
      strcpy( str, "----------" ); /* default=no perms */
      
      if ( S_ISDIR(mode) ) str[0] = 'd'; /* directory? */
      if ( S_ISCHR(mode) ) str[0] = 'c'; /* char devices */
      if ( S_ISBLK(mode) ) str[0] = 'b'; /* block device */
      if ( S_ISLNK(mode) ) str[0]='l'; //link
      
      if ( mode & S_IRUSR ) str[1] = 'r'; /* 3 bits for user */
      if ( mode & S_IWUSR ) str[2] = 'w';
      if ( mode & S_IXUSR ) str[3] = 'x';
      
      if ( mode & S_IRGRP ) str[4] = 'r'; /* 3 bits for group */
      if ( mode & S_IWGRP ) str[5] = 'w';
      if ( mode & S_IXGRP ) str[6] = 'x';
      
      if ( mode & S_IROTH ) str[7] = 'r'; /* 3 bits for other */
      if ( mode & S_IWOTH ) str[8] = 'w';
      if ( mode & S_IXOTH ) str[9] = 'x';
  }

#include <pwd.h>

char *uid_to_name( uid_t uid )
/*
 * returns pointer to username associated with uid, uses getpw()
 */
{
    struct passwd *getpwuid(), *pw_ptr;
    static char numstr[10];
    
    if ( ( pw_ptr = getpwuid( uid ) ) == NULL ){
        sprintf(numstr, "%d", uid);
        return numstr;
    }
    else
        return pw_ptr->pw_name ;
}

#include <grp.h>

char *gid_to_name( gid_t gid )
/*
 * returns pointer to group number gid. used getgrgid(3)
 */
{
    struct group *getgrgid(), *grp_ptr;
    static char numstr[10];
    
    if ( ( grp_ptr = getgrgid(gid) ) == NULL ){
        sprintf(numstr, "%d", gid);
        return numstr;
    }
    else
        return grp_ptr->gr_name;
}

struct NODE {
    struct NODE *left;
    int depth;
    int dflag; //indicates spacing
    int eflag; //indicates executable file
    char *fname;
    int value; //filetype
    struct NODE *right;
    struct NODE *dirtree;
};
struct NODE *root=NULL;
struct NODE *nodeptr;


void insert( struct NODE *curr, struct NODE *new ) {
    
    new->right=NULL;
    new->left=NULL;
    if(curr->value==NULL) curr=new;
    
    else if(new->value <= curr->value) {
        if(curr->left != NULL)
            insert(curr->left, new);
        
        else
            new->depth++;
        curr->left = new;
    }
    else {
        if(curr->right != NULL)
            insert(curr->right, new);
        else{
            curr->right = new;new->depth++;}
    }
}

void inorder(struct NODE *curr) {
    if(curr->left != NULL) inorder(curr->left); /*step-1 & step-2*/
    //printf("%d", curr->value); /*step-3*/
    printfile(curr);
    if(curr->right != NULL) inorder(curr->right); /*step-4*/
}

void printfile(struct NODE *curr) {
    if(curr->eflag==1 && flag==1) printf( "%s*\n" , curr->fname );
    if(curr->value==4 && flag==1) printf( "%s -> \n" , curr->fname );
    if(curr->value==1)
    { printf( "%s/\n" , curr->fname );
      inorder(curr->dirtree);
    }
}


/*
 void isdir(struct NODE *curr)
 {
 do_ls(curr->fname);
 }
 */


/*
 struct FILE
 {
 char type;
 struct NODE *
 }*/

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

int flag=0; 
//for option s
struct NODE
{
	struct NODE *left;
	int depth;
	int dflag; 
	//indicates spacing
	    int eflag; 
	//indicates executable file
	    char *fname;
	int value; 
	//filetype
	    struct NODE *right;
	struct NODE *dirtree;
};
struct NODE *root=NULL;
struct NODE *nodeptr;




void do_ls(char[]);
void dostat(char *);
void show_file_info( char *, struct stat *);
void mode_to_letters( int , char [] );
char *uid_to_name( uid_t );
char *gid_to_name( gid_t );
void insert( struct NODE *, struct NODE *);
void inorder(struct NODE *);
void printfile(struct NODE *);

int main(int ac, char *av[])
{
	char ch;

	while ((ch=getopt(ac, av, "s")) != -1) {
		if(ch=='s') flag=1;

		if ( ac == 1 )
			do_ls( "." );
		else
			while ( --ac ){
				printf("%s:\n", *++av );
				do_ls( *av );
			}
	}
}

void do_ls( char dirname[] )
{
	DIR *dir_ptr; /* the directory */
	struct dirent *direntp; /* each entry */

	if ( ( dir_ptr = opendir( dirname ) ) == NULL )
		fprintf(stderr,"ls1: cannot open %s\n", dirname);
	else
	{
		while ( ( direntp = readdir( dir_ptr ) ) != NULL )
			dostat( direntp->d_name );
		closedir(dir_ptr);
	}
}

void dostat( char *filename )
{
	struct stat info;

	if ( stat(filename, &info) == -1 ) /* cannot stat */
		perror( filename ); /* say why */
	else /* else show info */
		show_file_info( filename, &info );
}

void show_file_info( char *filename, struct stat *info_p )
/*
* display the info about 'filename'. The info is stored in struct at *info_p
*/
{
	char *uid_to_name(), *ctime(), *gid_to_name(), *filemode();
	void mode_to_letters();
	char modestr[11];

	mode_to_letters( info_p->st_mode, modestr );


	//if(modestr[0]=='d'){
		//struct NODE *root;
		//	}


	struct NODE *new;
	new=((struct NODE*)malloc(sizeof(struct NODE)));
	new->depth=0;
	new->fname=filename;
	new->dirtree=NULL;

	new->dflag=0;
	new->eflag=0;
	if(modestr[0]!='d' && (modestr[3]=='x' || modestr[6]=='x' || modestr[9]=='x')) new->eflag=1;
	//file is an executable

	    switch(modestr[0])
	{
	case 'd':
		new->value=1;
		new->dflag=1;
		do_ls(filename);

		//isdir(new);
		break;

	case 'c':
		new->value=2;
		break;

	case 'b':
		new->value=3;
		break;

	case 'l':
		new->value=4;
		break;

	default:
		break;
	}

	insert(root,new);


	//printf( "%s" , modestr );
	//printf( "%4d " , (int) info_p->st_nlink);
	//printf( "%-8s " , uid_to_name(info_p->st_uid) );
	//printf( "%-8s " , gid_to_name(info_p->st_gid) );
	//printf( "%8ld " , (long)info_p->st_size);
	//printf( "%.12s ", 4+ctime(&info_p->st_mtime));
	//printf( "%s\n" , filename );

}

/*
* utility functions
*/

/*
* This function takes a mode value and a char array
* and puts into the char array the file type and the
* nine letters that correspond to the bits in mode.
* NOTE: It does not code setuid, setgid, and sticky
* codes
*/
void mode_to_letters( int mode, char str[] )
{
	strcpy( str, "----------" ); /* default=no perms */

	if ( S_ISDIR(mode) ) str[0] = 'd'; /* directory? */
	if ( S_ISCHR(mode) ) str[0] = 'c'; /* char devices */
	if ( S_ISBLK(mode) ) str[0] = 'b'; /* block device */
	if ( S_ISLNK(mode) ) str[0]='l'; 
	//link

	    if ( mode & S_IRUSR ) str[1] = 'r'; /* 3 bits for user */
	if ( mode & S_IWUSR ) str[2] = 'w';
	if ( mode & S_IXUSR ) str[3] = 'x';

	if ( mode & S_IRGRP ) str[4] = 'r'; /* 3 bits for group */
	if ( mode & S_IWGRP ) str[5] = 'w';
	if ( mode & S_IXGRP ) str[6] = 'x';

	if ( mode & S_IROTH ) str[7] = 'r'; /* 3 bits for other */
	if ( mode & S_IWOTH ) str[8] = 'w';
	if ( mode & S_IXOTH ) str[9] = 'x';
}

#include <pwd.h>

char *uid_to_name( uid_t uid )
/*
* returns pointer to username associated with uid, uses getpw()
*/
{
	struct passwd *getpwuid(), *pw_ptr;
	static char numstr[10];

	if ( ( pw_ptr = getpwuid( uid ) ) == NULL ){
		sprintf(numstr,"%d", uid);
		return numstr;
	}
	else
		return pw_ptr->pw_name ;
}

#include <grp.h>

char *gid_to_name( gid_t gid )
/*
* returns pointer to group number gid. used getgrgid(3)
*/
{
	struct group *getgrgid(), *grp_ptr;
	static char numstr[10];

	if ( ( grp_ptr = getgrgid(gid) ) == NULL ){
		sprintf(numstr,"%d", gid);
		return numstr;
	}
	else
		return grp_ptr->gr_name;
}


void insert( struct NODE *curr, struct NODE *new )
{

	new->right=NULL;
	new->left=NULL;
	if(curr->value==NULL) curr=new;

	else if(new->value <= curr->value)
	{
		if(curr->left != NULL)
			insert(curr->left, new);

		else
			new->depth++;
		curr->left = new;
	}
	else
	{
		if(curr->right != NULL)
			insert(curr->right, new);
		else{
			curr->right = new;
			new->depth++;
		}
	}
}

void inorder(struct NODE *curr)
{
	if(curr->left != NULL) inorder(curr->left); /*step-1 & step-2*/
	//printf("%d", curr->value); /*step-3*/
	printfile(curr);
	if(curr->right != NULL) inorder(curr->right); /*step-4*/
}

void printfile(struct NODE *curr)
{
	if(curr->eflag==1 && flag==1) printf( "%s*\n" , curr->fname );
	if(curr->value==4 && flag==1) printf( "%s -> \n" , curr->fname );
	if(curr->value==1)
	{ 
		printf( "%s/\n" , curr->fname );
		inorder(curr->dirtree);
	}
}


/*
void isdir(struct NODE *curr)
{
do_ls(curr->fname);
}
*/


/*
struct FILE
{
char type;
struct NODE *
}
*/