Use lsof to view open files by processes: 1. Run lsof for all open files. 2. Use lsof -i for network connections. 3. Use lsof -p PID for files opened by a specific process.

To view open files by processes in Linux, use the `lsof` command. For example: 1. Run `lsof` to list all open files. 2. Use `lsof -i` for network connections. 3. Try `lsof -p PID` to see files opened by a specific process.