execlike

Execlike is a term used in computing to describe a family of interfaces that emulate the behavior of the Unix exec family functions (exec, execl, execle, execlp, execv, execve). These APIs are designed to replace the current process image with a new executable image. In typical implementations, an execlike call takes a path to an executable, followed by a sequence of argument strings, ending with a NULL terminator. Some variants also take an environment pointer to supply the new process environment. If the call succeeds, control never returns to the caller; if it fails, the function returns an error value and sets an error indicator such as errno on POSIX systems.

Across platforms, execlike interfaces are implemented differently. POSIX-compliant systems provide the exec family with direct process replacement. Windows does not offer a true single-call replace-the-process primitive; similar behavior is achieved via creation of a new process and exiting the current one, or via language-specific wrappers.

In practice, execlike patterns appear in multiple languages through wrappers named similarly to exec*, including C libraries, Python's os.exec* functions, and other runtime environments. They are used for tasks such as launching a program from a script, replacing a faulty process, or implementing command shells and launchers.

See also: exec family, os.exec*, CreateProcess, process replacement, replacement of a process image.