<?php
＄myfile = fopen ('new_school_file.txt", "w" or die ("unable to open file!");
＄txt = "schoolname \n';
fwrite (＄myfile. ＄txt);
＄txt= "studentname \n";
fwrite (＄myfile, $txt);
fclose (＄myfile);
?>

The fclose ( ) function is used to close an opened file. The file odject comes from fopen function.
Syntax:
fclose($file_Object);
Example:
< ?php
＄myfile = fopen("student.txt", "r'');
/ / some code to be executed ....
fclose( ＄myfiIe);
? >

The fread ( ) function, is used read from an open fîle. The file object comes from fopen function.
Syntax:
fread(＄file_Object,filesize("FileName''));
Example:
< ?php
fread (＄myfiIe,filesize("Student. txt''));
? >

(i) The file_put_contents() function is used to append to a file.
(ii) Parameters used in appending a file are file, data, mode and context.
1. File - Specifies the file to write to. If the file does not exist, this function will create one.
2. data - can be a string, an array or a data stream to write to the file.
3. mode - specifies how to open/write to the file.
4. context - context is a set of options that can modify the behaviour of a stream.

(i) Check box is the important feature which selects more than one value from the HTML form.
(ii) Radio box is similar to checkbox but one value can be chosen at a time.

(i) In the web development, user access website or web pages from remote client machine and feed the data to server.
(ii) These data are collected via HTML form controls like text box" dropdown box and radio button, etc. and sent to server using server side programming like PHP.

The file_put_contents ( ) function is used to Append to a file.
Syntax:
file_put_contents(file,data,mode,context)
Example:
< ?php
＄txt = "Student id ";
＄myfile = file_put_contents('logs.txt', $txt.
PHP_EOL , FILE_APPEND | LOCK_EX);
? >

PHP write a File:
The fwrite( ) function is used to write to a file.
Syntax:
fwrite(＄myfile, ＄txt);
Example:
< ?php
＄myfile = fopen("new_schooLfile.
txt", "w'')
or die("Unable to open file!'');
＄txt = "School Name\n";
fwrite(＄myfile, ＄txt);
＄txt = "Student Name\n";
fwrite(＄myfile, ＄txt);
fclose(＄myfile);
? >

PHP Close a File:
The fclose ( ) function is used to close an opened file.
The file object comes from fopen function.
Syntax:
fclose($file_Object);
Example:
< ?php
＄myfile = fopen("student.txt", "r'');
/ / some code to be executed ....
fclose( ＄myfiIe);
? >

PHP Read a File:
The fread ( ) function reads from an open file.
The file object comes from fopen function.
Syntax:
fread(＄file_Object,filesize("FileName''));
Example:
< ?php
fread (＄myfiIe,filesize("Student. txt''));
? >

PHP Open a File
1. fopen( ) is a system function available in PHP.
2. This function helps to open a file in the server.
3. It contains two parameters one for the file and the other one specifies in which mode the file should be opened (Read/Write).
Syntax:
＄file_Object= . fopen("FileName", "Read/ WriteMode'') or die("Error Message!'');
Example:
< ?php
＄myfile = fopen("Student.txt", "r'') or die("Unable to open file!'');
? >

Validation rules for HTML input field:

< html >
< head >
< title > Login Form < /title >
< body >
< h3 align=center > TamiiNadu State Council of
EducationalResearchand Training, Chennai < /h3 >
< Form Action = "mailto:abcd.xyz@com"
method =post >
< p > User Name:
OUTPUT:
< Input type = text name="user_name" size = 20 maxlength = 15 > < /p >
< p > Password:
< Input type = password name="pass" size = 20 maxlength = 15 > < /p >
< Input type = reset value = "Clear" >
< Input type = submit value = "Login" >
< /Form >
< /body >
< /html >

i) Text(Notepad) file:
AJAX = Asynchronous JavaScript and XML
CSS = Cascading Style Sheets
HTML = Hyper Text Markup Language
PHP = PHP Hypertext: Preprocessor
SQL = Structured Query Language
SVG = Scalable Vector Graphics
XML = EXtensible Markup Language
ii) PHP File:
< ?php
＄myfile = fopen("webdictionary.txt", "r'') or
die("Unable to open file!'');
echo fread( ＄myfile, filesize("webdictionary.
txt'')); fclose(＄myfile);
? >
iii) OUTPUT 
AJAX = Asynchronous JavaScript and XML
CSS = Cascading Style Sheets
HTML = Hyper Text Markup Language
PHP = PHP Hypertext Preprocessor
SQL = Structured Query Language
SVG = Scalable Vector Graphics
XML = EXtensible Markup Language