Prog_2 course- 2014

2 bytes team

Kinan keshkeh

IT Engineering-Damascus University

3rd year

Binary files

files are divided into :

Binary files

Text files

1. Definition

2. Assign

3. Initialize :

4. Operations :

5. Close

Files

Rewrite

Reset

append

Write

writeln

Read

Readln

In the same way we define

Binary files but there are

some changes

Let’s go ....

Binary file

It is a type of files that has the same kind of elements and each element inside binary file has the same

size …..

1) Definition :

var filename : file of <type>;

• filename : name from user

• file of : Two words are reserved

• type : any type standard or structure ( char ,integer , string , array , record ……)

Ex: 1. Type person=record

fname: string[20];

lname: string[25];

age: integer;

end;

Var f1 : file of person ;

2. Var f2: file of char ;

3. Type arr=array[1..100] of real;

Var f3: file of arr ;

Note : Binary files are similar to arrays but there are

Two different points …

A. Accessible to the element

B. Size

fname lname

age

fname lname

age

fname lname

age

fname lname

age

fname lname

age ……….

fname lname

age

20 bytes

25 bytes

2 bytes

{ 47 bytes }

Seek(f1,0)

Seek(f1,filesize(f))

Seek(f1,2)

Seek(f1,1)

2) Assign :

Assign(f1,’c:\myfile.bin’);

3) Initialize :

A. Rewrite(f) : Used when we want to write or adjustment on a binary file

B. Reset(f) : Used when we want to read on a binary file

4) Operations :

A. Write : access to data when we initialize binary file to write

B. Read : access to data when we initialize binary file to read

5) close : to save changes or store data in binary file

Functions uses in binary files :

1. Seek(filename, i) : Used to move the cursor to element number (i) where counting starts from

For example seek(f,5)

2. Eof(filename) :return true when file ends

3. Filesize(f) : return The number of elements in binary file

Note : we use these functions only when initialize binary file to read

Note : we don’t use eoln(f) in binary file because

there are no lines

zero

Lets make it

real :D !!

hard Exercise public (8) :أكتة ترَايجا يقىو تانعًهياخ انتانيح

يىصف انكتاب ترقى , نًعطياخ تعريف انكتة في يكتثح يهف ثُائي في انخزٌ 1.إضافح إنى حقم يُطقي , وتاريخ اإلصذار , ًؤنفانواسى , وعُىاٌ , تسهسهي .َصيانثرَايج تقراءج انًعطياخ يٍ يهف يقىو ....اإلعارجيذل عهى

يقىو انًستخذو تئعطاء جذول تأرقاو انكتة , اإلعارج أو اإلعادج في انًهفتسجيم 2. .انًهفانثرَايج عهى نيسجهها , وانًعادجانًعارج

.الئحح تانكتة انًعارجإظهار 3.

طثاعح تاريخ إصذار انكتاب انخايس وانكتاب األخير في انًهف : طهة إضافي 4. انثُائي

Program 2_bytesprog

Uses wincrt

Type Date=record

day:1..31;

month:1..12;

year:1900..2013;

end;

Book=record

number : integer;

title,author: string[30];

pub_date : Data;

borrowed : Boolean;

end;

Var : f_text :text;

f_bin,temp :file of Book;

i,j,n : integer;

abook: book;

C: char; found: Boolean;

Borrowed_book : array of integer;

Begin

assign(f_text ,’c:\text.txt’);

assign(f_bin ,’c:\binary.bin’);

reset(f_text);

rewrite(f_bin);

while not eof(f_text) do begin with abook do begin

readln(f_text,number,author,title,pub_date.day,c,

pub_date.month,c,pub_date.year,c);

if c='y' then borrowed:=true; if c='n' then

borrowed:=false;

end; {with}

write(f_bin,abook); end; {while}

close(f_text);

close(f_bin);

+1 +2

writeln('enter the total number of the lend books');

readln(n);

for i:=1 to n do

begin

writeln('enter the number of the book'); readln(Borrowed_book[i]);

end;

Assign(temp,’c:/myfile.bin)

reset(f_bin);

rewrite(temp);

While not eof(f_bin) do begin read(f_bin,abook); found:=false; i:=1; while i<=n and not found do begin if Borrowed_book[i]=abook.number then found:= true; i:=i+1; end; if found then abook.borrowed:=true; write(temp,abook); end;

close(f_bin);

close(temp);

Reset(temp);

rewrite(f_bin);

while not eof(temp) do

begin

read(temp,abook);

write(f_bin,abook);

end;

close(temp);

close(f_bin);

rewrite(temp);

close(temp);

Reset(f_bin);

While not eof(f_bin) do

begin

Read(f_bin,abook);

If (abook.borrowed) then

Writeln(abook.number,’ ‘ ,abook.title);

end;

Seek(f_bin,4);

Read(f,abook);

Writeln(‘the book number five has appeared in : ‘,abook.day, ‘ ‘ ,abook.month, ‘ ‘ ,abook.year);

Seek(f_bin,filesize(f_bin));

Read(f,abook);

Writeln(‘the last book has appeared in : ‘,abook.day, ‘ ‘ ,abook.month, ‘ ‘ ,abook.year);

End.

Homework: لذٌىا ملفان ثىائٍان مه االعذاد الصحٍحة مزتبة تصاعذٌا وزٌذ

دمجهما بحٍث وحصل على ملف واحذ مزتب ٌحىي عىاصز الملفٍه سىقىم بالذمج دون استخذام الجذاول فً البزوامج

ألوىا وفتزض أن الملفان كبٍزان جذا و هذا ما وسمٍه بالفزس الخارجً

أكتب أوال بزوامجا ٌىشئ الملفات الثىائٍة مه ملفات 1. وصٍة تحىي أعذاد صحٍحة

أكتب بزوامج الذمج الذي ٌىشئ الملف الثىائً الىاتج 2.

أكتب الملف الثىائً الىاتج مجذدا فً ملف وصً 3.

Good luck…..

Group : group link

Mobile phone- Kinan : 0994385748

Facebook account : kinan’s account

2 bytes team