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.

efficient cleaning crew Park Ridge ...

In The News:

A phishing campaign impersonating OpenAI uses fake ChatGPT billing emails with a convincing login page to steal credentials and payment details.

Startups are helping modernize America’s defense industry with new technology and innovative ideas as the War Department diversifies its inventory.

New account fraud victims jumped 31% in 2025, reaching 5.4 million. Criminals open accounts you may never see on your regular bank statements.

Flytrex says its AI-powered Rooftop Dock system in Dallas-Fort Worth positions drones at restaurants before orders arrive, cutting delivery costs by 60%.

Samson Sky's Switchblade flying car secures $80 million from Dubai's Matin Group, but the redesigned hybrid-electric aircraft still needs more testing.

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

CenterPoint Energy confirmed customer data was stolen, while a hacker claims 7.49 million records with partial Social Security numbers were taken.

The $59 Brick device promises to help curb phone addiction, but free iPhone and Android tools may already do the job. Here's what to try first.

Epsilon Data Management's "opportunity seeker" lists helped scammers target millions of older Americans, DOJ court filings reveal in detail.

HBO Max's verified Reddit account was hijacked to push 108 malicious ads using ClickFix, a technique that tricks victims into running dangerous commands.

Flash Shelton reveals how home security cameras and alarm systems can stop squatters before they claim tenant rights in your vacant property.

WIM-Z's AI dog training robot uses on-device processing to detect barking and dispense treats autonomously, with field trials showing up to 83% reduction.

Google's Threat Intelligence Group found PROMPTFLUX malware that uses Gemini to rewrite its own code every hour, raising urgent cybersecurity alarms.

Your VPN may quietly drop protection when switching between airport Wi-Fi and hotel Wi-Fi. Key settings like auto-connect and kill switch help.

A South Carolina caregiver allegedly gained power of attorney over a 75-year-old with Parkinson's, then transferred his home via quitclaim deed for $5.

Joby Aviation flew its eVTOL air taxi into DFW Airport's busy airspace as Texas launches Project Nexus, a three-year advanced air mobility program.

Federal prosecutors say criminals bought sponsored search ads mimicking real banks, capturing over 5,000 login credentials and draining accounts.

The Mercedes-Benz eActros 600 electric truck targets 621 miles per charge on a 28,000-mile round-the-world journey through over 30 countries.

A viral video shows roughly a dozen Coco Robotics delivery robots swarming a Chicago sidewalk near Lincoln Park, raising wheelchair access concerns.

NewTree Social founder Maddy O'Connor built a community events app to help people discover local gatherings, wellness events and run clubs nearby.

DoppelCart's 119,000 fake shopping domains steal credit card details at checkout, mimicking over 44,000 real brands with convincing cloned sites.

Hurricane charity scams use data brokers and people search sites to target victims before storms even hit, exploiting personal information..

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

Autonomous race cars hit Laguna Seca and Imola Circuit at speeds topping 157 mph, but the Abu Dhabi Autonomous Racing League faces a fan problem.

A LinkedIn romance scam cost Gaby close to $1 million after a scammer returned her first payment to build trust, then escalated requests over two years.

CHMOD - Undertanding File Permissions on a Unix-Based Server

Web Hosting