Users are receiving permission-denied messages when trying to access a spreadsheet file within the company's file system. A Linux administrator receives a ticket and begin to investigate the following

top displays a real-time view of running processes ranked by CPU and memory usage and does not show open file handles or file-level access details.

nice adjusts the scheduling priority of a process and has no function related to listing or inspecting open files.

grep searches for text patterns within file contents or command output and does not enumerate which processes have a given file open.

lsof (list open files) produces output showing every file currently held open by a process, including the process name, PID, file descriptor, and access mode, which directly helps identify which processes are accessing a file and under what permissions. When users receive permission-denied errors on a specific file, lsof output showing that file's open handles gives the administrator precise visibility into process-level access conflicts or locking issues.