Linux에서 C로 짠 도서관리 프로그램.

// C로 짠 도서관리 프로그램.
    malloc과 sorting 그리고 file open 말고는 그다지 중요한건 없는듯?

invalid-file

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


typedef struct _booktype
{
  char book[30];
  char author[15];
  char publisher[15];
  char price[15];
  char year[15];
}booktype;

typedef struct _node
{
  booktype Data;
  struct _node *next;
}node;

int fileopen();
int checkfile(int iDs);    
void menulist();
void Datainput(booktype *Data);
void data_write(node *Head,int icnt,int iDs);
void datalist(node * Head,int icnt);
void release(node * Head);
node * read_data(int iDs,int icnt);
node * data_sort(node *Temp, node * Head);


int main()
{
  node Temp;
  node * Head;
  int Val;
  int iDs;
  int icnt;
 
  iDs = fileopen();
  icnt = checkfile(iDs);
 
  while(1)
  {
    Head = read_data(iDs,icnt);  
    menulist();
    fprintf(stdout, "Menu Select = ");
    fscanf(stdin,"%d", &Val);
    getchar();

    switch(Val)
    {

      case 1:
      {
        while(1)
        {
          Datainput(&Temp.Data);      
          Head = data_sort(&Temp,Head);
          icnt++;
          data_write(Head,icnt,iDs);
          break;
           
        }
        break;
      }
       
      case 2:
      {
        datalist(Head,icnt);
        break;
      }
       
      case 3:
      {
        release(Head);
        close(iDs);
        printf("Program Exit!!\n");
        return 0;
      }
      default:
        return 0;
    }
  }
 
  return 0;
}  

void menulist()
{
  fprintf(stdout,"\n");
  fprintf(stdout,"\t\t\t-------------\n");
  fprintf(stdout,"\t\t\t| 1. INSERT |\n");
  fprintf(stdout,"\t\t\t| 2. LIST   |\n");
  fprintf(stdout,"\t\t\t| 3. QUIT   |\n");
  fprintf(stdout,"\t\t\t-------------\n");
  fprintf(stdout,"\n");
}

int fileopen()
{
  int iDs;
  int iRen;
  char FHeader[30] = "******************************";
 
  iDs = open("Book.pdf",O_RDWR);
 
  if(-1 == iDs)
  {
    printf("\tNo Data File..!! Create DataFile? (choice: y or n) = ");
    iRen = fgetc(stdin);

    if(iRen == 'y')
    {
      iDs = open("Book.pdf", O_CREAT|O_RDWR, S_IRUSR|S_IWUSR|S_IXUSR);
      iRen = 0;
      write(iDs,&iRen,4);
      write(iDs,FHeader,30);
      lseek(iDs,34,SEEK_SET);
     
      return iDs;
    }
    else
    {
      printf("\tProgram Exit!!\n");
      exit(1);
    }
  }
 
  lseek(iDs,34,SEEK_SET);

  return iDs;
}


int checkfile(int iDs)
{
  int icnt;
 
  lseek(iDs,0,SEEK_SET);
  read(iDs,&icnt,4);
  printf("\n\n");
  printf("\tTotal Books = [%d] book\n", icnt);
 
  return icnt;
}


void Datainput(booktype *Data)
{
  int iRet;
 
  memset(Data,'0',sizeof(booktype));
 
  fprintf(stdout,"--------------------\n");
  fprintf(stdout,"BookName Input\n");
  iRet = read(0,Data->book,30);
  Data->book[iRet-1] = 0;

  fprintf(stdout,"Author input\n");
  iRet = read(0,Data->author, 15);
  Data->author[iRet-1] = 0;
 
  fprintf(stdout,"Publisher input\n");
  iRet = read(0,Data->publisher, 15);
  Data->publisher[iRet-1] = 0;
 
  fprintf(stdout,"Price input\n");
  iRet = read(0,Data->price, 15);
  Data->price[iRet-1] = 0;
 
  fprintf(stdout,"Year input\n");
  iRet = read(0,Data->year, 15);
  Data->year[iRet-1] = 0;
  fprintf(stdout,"--------------------\n");
}

node * read_data(int iDs,int icnt)
{
  node *Head=0;
  node *Temp;
  node *Back;
 
  lseek(iDs,34,SEEK_SET);
   
  for(;icnt!=0;--icnt)
  {
    Temp = malloc(sizeof(node));
   
    read(iDs,&Temp->Data,sizeof(booktype));
 
    if(Head == 0)    
    {
      Temp->next = 0;
      Head = Back = Temp;
    }
    else       
    {
      Back->next = Temp;
      Back=Temp;
      Temp->next = 0;
    }
    lseek(iDs,1,SEEK_CUR);
  }

  return Head;
}
   
node * data_sort(node *Temp, node * Head)
{
  node *Back;
  node *Pre;
 
  Back = Pre = Head;
 
  while(1)
  {
    if(Pre==0)
    {
      break;
    }
    if((strcmp(Pre->Data.book,Temp->Data.book)) > 0)
    {
      break;
    } 
    Back = Pre;
    Pre = Pre->next;
  }
  Temp->next = Pre;

  if(Pre == Head)
  {
    Head = Temp;
  }
  else
  {
    Back->next = Temp;
  }
  return Head;
}  
 

void data_write(node *Head,int icnt,int iDs)
{
  node *Temp;
 
  lseek(iDs,0,SEEK_SET);
  write(iDs,&icnt,4);
 
  lseek(iDs,34,SEEK_SET);
  while(1)
  {
    Temp = Head->next;
    write(iDs,&Head->Data,sizeof(booktype));
    write(iDs,"|",1);
   
    Head = Temp;
   
    if(Head==0)
    {
      break;  
    }
  }
}  
 

void datalist(node * Head,int icnt)
{
  node *Temp;
  node *Back;
  int iCnt1;

  Temp = Head;

  fprintf(stdout, "--------------------");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "------------\n");
  fprintf(stdout, " %s   ","Number");
  fprintf(stdout, "%11s","Book name");
  fprintf(stdout, "%15s","Author");
  fprintf(stdout, "%15s","Publisher");
  fprintf(stdout, "%10s","Price");
  fprintf(stdout, "%10s\n","Year");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "------------\n");

 
  for(iCnt1=1;iCnt1<=icnt;iCnt1++)
  {
    Back = Temp->next;
   
    fprintf(stdout, "  %d   ",iCnt1);
    fprintf(stdout, "%15s",Temp->Data.book);
    fprintf(stdout, "%15s",Temp->Data.author);
    fprintf(stdout, "%15s",Temp->Data.publisher);
    fprintf(stdout, "%10s",Temp->Data.price);
    fprintf(stdout, "%10s\n",Temp->Data.year);
 
    Temp = Back;
  }
  fprintf(stdout, "--------------------");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "--------------------");
  fprintf(stdout, "------------\n");
 
}

void release(node * Head)
{
  node * Temp;

  Temp = Head;

  while(1)
  {
    if(Temp == 0)
    {
      break;
    }

    Temp = Head->next;
    free(Head);
    Head = Temp;
  }

}