# File Descriptor Status: Growing A file descriptor is a process-local integer handle for an open I/O resource. ## Mental Model The process holds a table. The file descriptor is an index into that table. The table entry points to kernel state representing an open file, socket, pipe, terminal, or device. ## Standard Descriptors - `0`: stdin - `1`: stdout - `2`: stderr ## Why It Matters File descriptors explain many Linux behaviors: - Shell redirection. - Pipes. - Sockets. - Descriptor leaks. - Shared offsets after `dup`. ## Related - [[Articles/File Descriptors Part 1]] - [[Articles/File Descriptors Part 2]] - [[Articles/Tracing System Calls at a High Level]] - [[Topics/Linux & Systems]]