.elf File — Executable and Linkable Format

ELF (Executable and Linkable Format) is the standard binary format for executables, shared libraries, core dumps, and object files on Unix-like operating systems including Linux, BSD, Solaris, and many embedded systems. ELF was adopted as the standard Unix binary format in the 1990s, replacing older formats like a.out and COFF. The ELF format consists of an ELF header (identifying the file type, architecture, and entry point), program headers (describing segments for execution), and section headers (describing sections for linking). ELF supports multiple architectures (x86, ARM, MIPS, RISC-V, etc.), position-independent code (PIE) for ASLR security, dynamic linking through the PLT/GOT mechanism, and debug information through DWARF format sections. ELF files are produced by compilers (GCC, Clang, Rust) and processed by linkers (ld, lld, gold) and the dynamic linker (ld-linux.so). Tools like readelf, objdump, nm, and ldd inspect ELF file contents, symbols, and dependencies. The format's flexibility and well-documented specification have made it the universal binary format for non-Windows systems, from embedded microcontrollers to supercomputers.