Adding functionality to linked list implementation

[NatsoumiMaya]

hi ppl,
i have a code to write in C where i have to implement the mkdir, rm, rmdir and touch functions using double linked lists...im haveing trouble with it...here is what i have so far:
[code=c]
#ifndef _DIRECTORY_H
#define _DIRECTORY_H

/* tree node data structure declaration */

struct entryNode {
char * name;
struct entryNode * next; /* sibling */
struct entryNode * previous; /* sibling */
int isDirectory;
struct entryNode * parent;
union {
char * contents; /* if this node is a file, this contains the content of the file */
struct entryNode * entryList; /* if this node is a directory,
this contains a pointer to the first child inside the directory */
} entry;
};
[/code]
The rest of the file contains the function prototypes.


[code=c]

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "directory. h"

#define TRUE 1
#define FALSE 0

#define MAX_TEXT_SIZE 8192

/* used as a temp storage for the text content of a file */
char tmpbuf[MAX_TEXT_SIZE];

/* pointer to the root node of the file system */
struct entryNode * root;

/* Helper functions */
void pwdHelper (struct entryNode *); /* don't worry about this one */


/* Return a pointer to the entry with the given name in the given list,
or NULL if no such entry exists. */
/* basically it searches for the file/dir name at the current level:
* it does not go into directories */
struct entryNode * located (char * name, struct entryNode * list) {
if (list == NULL) {
return NULL;
} else if (strcmp (list->name, name) == 0) {
return list;
} else {
return located (name, list->next);
}
}

/* implements the "touch" command (one argument; not in standard UNIX) */
/* wd is a pointer to the current working directory */
void touchFile (struct entryNode * wd, char * fileName)
{

struct entryNode * newFile;

if (located (fileName, wd->entry.entryLis t))
{
printf ("touch: %s: File exists\n", fileName);
return;
}

/* initialize temporary text buffer to zeros */
bzero(tmpbuf,MA X_TEXT_SIZE);

/* HELP NEEDED HERE*/
}

/* implements the "mkdir" command (one argument; no options) */
void createDir (struct entryNode * wd, char * dirName) {
struct entryNode * newDir;

if (located (dirName, wd->entry.entryLis t))
{
printf ("mkdir: %s: File exists\n", dirName);
return;
}
/*struct entryNode * newDir = (char *) malloc(sizeof(n ewDir));*/
newDir->entry.entryLis t;
newDir->next = NULL;
/*newDir->previous = dirName;*/
/*dirName->next = newDir;*/
struct entryNode * entryList = NULL;
/*HELP NEEDED WITH BOLDED TEXT*/
}

/* implements the "rm" command (one argument, unlike standard UNIX; no options) */
void removeFile (struct entryNode * wd, char * fileName) {
struct entryNode * file;
file = located (fileName, wd->entry.entryLis t);

if (file == NULL)
{
printf ("rm: %s: No such file or directory.\n", fileName);
return;
}

else if (file->isDirectory)
{
printf ("rm: %s: is a directory.\n", fileName);
return;
}
/*HELP NEEDED HERE*/
}

/* implements the "rmdir" command (one argument, unlike standard UNIX; no options) */
void removeDir (struct entryNode * wd, char * dirName) {
struct entryNode * dir;
struct entryNode * tmp;

dir = located (dirName, wd->entry.entryLis t);
if (dir == NULL)
{
printf ("rmdir: %s: No such file or directory.\n", dirName);
return;
}

else if (!dir->isDirectory)
{
printf ("rmdir: %s: Not a directory.\n", dirName);
return;
}

else if (dir->name[0] =='/')
{
printf("rmdir: Cannot delete root directory.\n");
return;
}
[B]else
{
previousfile = file->previous;
nextfile = file->next;
if (previousfile== NULL)
{
printf("%s: No Previous File");
if (nextfile == NULL)
{
printf("%s: No Next File");
}
free(file);
wd->entry.entryl it = NULL;
}
else if
{
if (nextfile == NULL)
{
printf("%s: No Next File");
if (previousfile== NULL)
{
printf("%s: No Previous File");
}
free(file);
wd->entry.entryl it = NULL;
}
}
else
{
free(file);
wd->entry.entryl it = NULL;
}
}

/* HELP NEEDED WITH BOLDED TEXT */

/* implements the "mv" command (two arguments, unlike standard UNIX; no options) */
void moveEntry (struct entryNode * wd, char * from, char * to) {
struct entryNode * fromNode;
struct entryNode * toNode;
fromNode = located (from, wd->entry.entryLis t);
if (fromNode == NULL)
{
printf ("mv: %s: No such file or directory.\n", from);
return;
}

/*HELP NEEDED HERE */
}
[/code]
THANK YOU IN ADVANCE FOR YOUR HELP ^_^