What are best practices for setting file permissions in PHP applications?

When setting file permissions in PHP applications, it is important to follow best practices to ensure security and proper access control. One common approach is to set file permissions to allow only the necessary level of access for each user or group, such as read, write, and execute permissions. It is also recommended to avoid using overly permissive permissions, such as 777, which can pose security risks.

// Set file permissions to allow only the necessary level of access
chmod("/path/to/file.txt", 0644);