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.

disinfecting cleaning services Arlington Heights ..

In The News:

Malicious Chrome and Edge extensions collected browsing history, keystrokes and personal data from millions of users before Google and Microsoft removed them.

Google's new Call Reason feature lets Android users mark calls as urgent before dialing, displaying an urgent label to recipients using Phone by Google app.

Medical history made as surgeons successfully restore sight to legally blind patient using world's first 3D printed corneal implant grown from human cells.

Data brokers aggressively collect your holiday shopping data to fuel scams and targeted ads. Learn how to delete your digital profile before 2025 starts.

Scammers are sending fake MetaMask wallet verification emails using official branding to steal crypto information through phishing links and fraudulent domains.

Learn what background permissions, push notifications, security updates, auto-join networks and app refresh mean to better manage your phone's privacy settings.

Criminals test stolen data by applying for deposit accounts in victims' names to prepare bigger attacks. Learn why banks won't share fraud details.

New study of 10,500+ kids reveals early smartphone ownership linked to depression, obesity, and poor sleep by age 12. Earlier phones mean higher risks.

A phone phishing attack compromised Harvard's alumni and donor database, marking the second security incident at the university in recent months.

AutoFlight's zero-carbon floating vertiport uses solar power to charge eVTOL aircraft while supporting emergency response, tourism, and marine energy maintenance.

A new phone return scam targets recent buyers with fake carrier calls. Learn how criminals steal devices and steps to protect yourself from this fraud.

New Anthropic research reveals how AI reward hacking leads to dangerous behaviors, including models giving harmful advice like drinking bleach to users seeking help.

The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.

Holiday email scams, including non-delivery fraud and gift card schemes, spike in November and December, costing victims hundreds of millions, the FBI says.

Holiday visits offer the perfect opportunity to help older parents with technology updates, scam protection and basic troubleshooting skills for safer digital experiences.

Swiss scientists create grain-sized robot that surgeons control with magnets to deliver medicine precisely through blood vessels in medical breakthrough.

Researchers exploited WhatsApp's API vulnerability to scrape 3.5 billion phone numbers. Learn how this massive data breach happened and protect yourself.

Travel companies share passenger data with third parties during holidays, but travelers can protect themselves by removing data from broker sites and using aliases.

Xpeng's humanoid robot moves so realistically that crowds believed it was fake, marking a major advancement in robotics technology ahead of 2026 commercial launch.

Researchers discover phishing scam using invisible characters to evade email security, with protection tips including password managers and two-factor authentication.

iPhone and Android users can reduce battery drain and data usage by restricting Background App Refresh to Wi-Fi connections instead of mobile networks.

Scammers nearly stole an Apple account by exploiting the support system with authentic-looking tickets and phone calls, users can protect themselves with safety steps.

FoloToy restored sales of its AI teddy bear Kumma after a weeklong suspension following safety group findings of risky and inappropriate responses to children.

Threat intelligence firm Synthient uncovers one of the largest password exposures ever, prompting immediate security recommendations.

Viral video shared by Elon Musk shows Tesla's Optimus humanoid robots performing tasks from cooking to construction, garnering over 58.5 million views on social media.

CHMOD - Undertanding File Permissions on a Unix-Based Server

Web Hosting