What is the meaning of chmod 777?
In short, “chmod 777” means making the file readable, writable and executable by everyone. chmod 775 /path/to/file. Hopefully, this article can help you understand better about the file permissions in Unix system and the origin of the magical number “777”.
Each octal digit is the sum of 4 if read permission is granted, 2 if write permission is granted and 1 if execute permission is granted. Here are the most commonly needed permissions: 755 means you can do anything with the file or directory, and other users can read and execute it but not alter it.
- In short, “chmod 777” means making the file readable, writable and executable by everyone. chmod 775 /path/to/file. Hopefully, this article can help you understand better about the file permissions in Unix system and the origin of the magical number “777”.
- A Sticky bit is a permission bit that is set on a file or a directory that lets only the owner of the file/directory or the root user to delete or rename the file. No other user is given privileges to delete the file created by some other user.
- Basically it means you can tell the operating system to run the code in the file. For example, if the file was a binary executable, write access would allow you to modify it, read access would allow you to view it, but without execute permissions you would not be able to run the program.
Access control list (ACL) provides an additional, more flexible permission mechanism for file systems. It is designed to assist with UNIX file permissions. ACL allows you to give permissions for any user or group to any disc resource.
- A standard ACL can permit or deny trafiic based only on the source address(s). takes numbers1-99. An extended ACL can permit or deny traffic based on both the source and destination address(s) as well as tcp/udp/icmp trafic types.
- An access control list (ACL) is a list of access control entries (ACE). Each ACE in an ACL identifies a trustee and specifies the access rights allowed, denied, or audited for that trustee. The security descriptor for a securable object can contain two types of ACLs: a DACL and a SACL.
- Reflexive access lists allow IP packets to be filtered based on upper-layer session information. You can use reflexive access lists to permit IP traffic for sessions originating from within your network but to deny IP traffic for sessions originating from outside your network.
Updated: 2nd October 2019