Home
>
Web Hosting
>
CHMOD - Undertanding File Permissions on a Unix-Based Server

CHMOD - Undertanding File Permissions on a Unix-Based Server

The basic command for changing file permissions in unix based operating systems is the 'chmod' command. This command is executed with a set of parameters after it. With most FTP clients, you can simply select the filename you want to change the permissions of, right click, and choose the chmod command.

There are three main groups of permissions when dealing with the chmod command. The three groups are yourself or owner, your unix group, and everyone else. A typical chmod command would look like this - 'chmod 755' This allows you to add, remove or rename files as well as read or edit a file. It also specifies that your unix group and everyone else can only read and edit the file in question. They can't add, delete, or rename the file.

How the numbers in the chmod command work

There are three types of permissions that can be given to a file. They are read, write, and execute. The read permission is assigned a value of 4, the write permission is assigned a value of 2 and the execute permission is assigned a value of 1. So when a chmod command specified the digit 7 as the first number, it means that all three types of permissions are to be assigned to it. If a party is assigned a value of '0' then it means it has no rights whatsoever to a file. '6' tells the server that the user can read and write to the file but can't execute it. I think you get the idea.

Common permissions to set

Most of your html files will do fine with a permission of 644. Most script files will need a permission of 755. Any configuration files in a script package will often need a file permission of 777. Be very careful about assigning a file permission of '777' for everyone. With this permission, it means that anyone who gains access to your server will be able to add, remove, rename, read or edit the file. It is always a good idea with security in mind to assign the least amount of permissions necessary to get the job done.

An FTP client can keep things simple

Most people on shared servers will not have access to a command line to be able to use the chmod command. For most people, changing file permissions will be done through an FTP client. To do this, right click on the file you want to alter, and choose the chmod command. You will usually get a popup that will show nine checkboxes. The will be arranged in three rows. On the left you will usually see Read, Write, and Execute for the row headings. You can accomplish the same thing as typing in the numbers above by clicking on one, two or three boxes for each party. Once you're done, you click the apply or ok button and the file permissions will be changed.

If you keep in mind that you need to always go with the most restrictive file permissions possible that still allows your files to execute, and that there are three parties to define permissions for, you'll do fine. The three parties again are the owner, group, and everyone else.

This article was written by Joe Duchesne, president of http://www.yowling.com/, a web hosting company that specializes in helping online business owners increase their website traffic. Copyright 2004 Yowling. Reprint Freely as long as you link back to my website from this resource box.

cleaning service near Bannockburn ..

In The News:

Phishing scammers use rnicrosoft.com domain to impersonate Microsoft by replacing "m" with "rn" in typosquatting attacks that steal login credentials.

OpenAI announces new teen safety rules for ChatGPT users under 18, blocking romantic roleplay and requiring extra caution on body image topics.

A 2025 data breach at fintech company 700Credit exposes personal information of more than 5.8 million people through compromised third-party integration partner.

Retailers lose $76.5 billion annually to return fraud as nearly 10% of U.S. retail returns involve fraudulent activity, with $850 billion in returns expected in 2025.

ShinyHunters claims responsibility for stealing 94GB of Pornhub user data affecting over 200 million records and demands Bitcoin ransom.

ChatGPT 2025 now connects to Apple Music, Canva, Expedia, TripAdvisor and OpenTable through built-in apps that help users create playlists, design graphics and more.

Apple releases emergency patches for two zero-day vulnerabilities actively exploited in attacks. iPhone and iPad users urged to update immediately.

DoorDash launches Zesty, an AI-powered social app that recommends restaurants through conversational search, now testing in San Francisco and New York.

Cybersecurity firm Infoblox reveals that over 90 percent of parked domains now redirect visitors to scams and malware, making simple typos extremely dangerous.

The Fox News AI Newsletter covers the latest artificial intelligence technology advancements, including the challenges and opportunities AI presents now and for the future.

GPT-5.2 is now live for all ChatGPT users with improved coding, writing and image interpretation, with Kurt Knutsson offering his review.

New iPhone replacement scam uses pressure tactics and fake carrier calls to steal devices from buyers. Criminals claim shipping errors and demand urgent returns.

Amazon Ring's new facial recognition feature sparks privacy controversy as Electronic Frontier Foundation critics argue the AI upgrade expands surveillance risks.

New Android banking trojan Sturnus steals credentials, reads encrypted messages and controls devices.

Denmark's 3D-printed student village proves automation builds 36 apartments faster than traditional methods. Skovsporet project shows housing future.

Discover Android's new Sound Notifications feature that alerts you to smoke alarms, doorbells, and baby cries even when wearing headphones.

New SantaStealer malware reportedly threatens holiday shoppers with password theft. This Christmas-themed info-stealer targets browsers and crypto wallets.

The Christmas season brings a surge in Netflix phishing scams targeting shoppers with fake emails. Stacey P received convincing scam but verified account first.

San Francisco Giants invite Jamie Grohsong to throw ceremonial first pitch at Oracle Park after he learned to play baseball with a bionic hand following an injury.

FBI warns cybercriminals are stealing family photos from social media to create fake proof of life images in virtual kidnapping scams targeting victims.

Instagram's new 'Your Algorithm' tool lets you control your Reels feed in real time. The app now gives you power to customize what videos you see.

Major Marquis fintech breach exposes 400,000-plus Americans' data through unpatched SonicWall vulnerability, with Texas hardest hit at 354,000 affected.

Free up iPhone storage fast by clearing large photos and videos from Messages app. Simple steps for iOS users to delete attachments without losing chats.

Scammers are flooding inboxes with fake tracking alerts that mimic real carriers, exploiting the holiday rush to steal logins and personal data.

The Fox News AI Newsletter brings you the latest news on AI technology advancements and the challenges and opportunities AI presents now and for the future.

CHMOD - Undertanding File Permissions on a Unix-Based Server

Web Hosting