search
HomeBackend DevelopmentPHP TutorialDetailed explanation of php fwrite() function writing file example

php What does the fwrite() function do?

In php, the php fwrite() function is used to write files (safe for binary files). It is to add a new element to the file. Let’s take a look at its syntax:

Syntax

fwrite(file,string,length)

Parameter details:


Parameters Description
file Required. Specifies the open file to write to.
string Required. Specifies the string to be written to the open file.
length Optional. Specifies the maximum number of bytes to be written.


Description

fwrite() writes the contents of string to the file Pointer to file. If length is specified, writing will stop when length bytes have been written or when the string has been written, whichever occurs first.

The fwrite function is successfully executed and returns the number of bytes written. On failure, returns FALSE.

Example

php fwrite() function example, the code is as follows:

<?php
 $file = fopen("test.txt","w");
 echo fwrite($file,"Hello World. Testing!");
 fclose($file);
 ?>

Detailed explanation of the example:

Use the fwrite function, to A file named test.txt, add the string "Hello World. Testing!" to it.

Code running results:

21

If we open the test.txt file at this time, we will see the newly added content "Hello World. Testing!".

[Recommended related articles]:

Detailed example of php fwrite() function appending and newline writing

The above is the detailed content of Detailed explanation of php fwrite() function writing file example. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
What data can be stored in a PHP session?What data can be stored in a PHP session?May 02, 2025 am 12:17 AM

PHPsessionscanstorestrings,numbers,arrays,andobjects.1.Strings:textdatalikeusernames.2.Numbers:integersorfloatsforcounters.3.Arrays:listslikeshoppingcarts.4.Objects:complexstructuresthatareserialized.

How do you start a PHP session?How do you start a PHP session?May 02, 2025 am 12:16 AM

TostartaPHPsession,usesession_start()atthescript'sbeginning.1)Placeitbeforeanyoutputtosetthesessioncookie.2)Usesessionsforuserdatalikeloginstatusorshoppingcarts.3)RegeneratesessionIDstopreventfixationattacks.4)Considerusingadatabaseforsessionstoragei

What is session regeneration, and how does it improve security?What is session regeneration, and how does it improve security?May 02, 2025 am 12:15 AM

Session regeneration refers to generating a new session ID and invalidating the old ID when the user performs sensitive operations in case of session fixed attacks. The implementation steps include: 1. Detect sensitive operations, 2. Generate new session ID, 3. Destroy old session ID, 4. Update user-side session information.

What are some performance considerations when using PHP sessions?What are some performance considerations when using PHP sessions?May 02, 2025 am 12:11 AM

PHP sessions have a significant impact on application performance. Optimization methods include: 1. Use a database to store session data to improve response speed; 2. Reduce the use of session data and only store necessary information; 3. Use a non-blocking session processor to improve concurrency capabilities; 4. Adjust the session expiration time to balance user experience and server burden; 5. Use persistent sessions to reduce the number of data read and write times.

How do PHP sessions differ from cookies?How do PHP sessions differ from cookies?May 02, 2025 am 12:03 AM

PHPsessionsareserver-side,whilecookiesareclient-side.1)Sessionsstoredataontheserver,aremoresecure,andhandlelargerdata.2)Cookiesstoredataontheclient,arelesssecure,andlimitedinsize.Usesessionsforsensitivedataandcookiesfornon-sensitive,client-sidedata.

How does PHP identify a user's session?How does PHP identify a user's session?May 01, 2025 am 12:23 AM

PHPidentifiesauser'ssessionusingsessioncookiesandsessionIDs.1)Whensession_start()iscalled,PHPgeneratesauniquesessionIDstoredinacookienamedPHPSESSIDontheuser'sbrowser.2)ThisIDallowsPHPtoretrievesessiondatafromtheserver.

What are some best practices for securing PHP sessions?What are some best practices for securing PHP sessions?May 01, 2025 am 12:22 AM

The security of PHP sessions can be achieved through the following measures: 1. Use session_regenerate_id() to regenerate the session ID when the user logs in or is an important operation. 2. Encrypt the transmission session ID through the HTTPS protocol. 3. Use session_save_path() to specify the secure directory to store session data and set permissions correctly.

Where are PHP session files stored by default?Where are PHP session files stored by default?May 01, 2025 am 12:15 AM

PHPsessionfilesarestoredinthedirectoryspecifiedbysession.save_path,typically/tmponUnix-likesystemsorC:\Windows\TemponWindows.Tocustomizethis:1)Usesession_save_path()tosetacustomdirectory,ensuringit'swritable;2)Verifythecustomdirectoryexistsandiswrita

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

SublimeText3 Linux new version

SublimeText3 Linux new version

SublimeText3 Linux latest version

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.