ShellExecute

ShellExecute is a Windows API function from the Shell API that performs an operation on a specified file or object, such as opening a document with its associated application, printing, or exploring a folder. It is implemented in shell32.dll and is accessible from C/C++ and other languages via the shellapi.h header.

Signature and variants: HINSTANCE ShellExecute(HWND hwnd, LPCSTR lpOperation, LPCSTR lpFile, LPCSTR lpParameters, LPCSTR lpDirectory, INT nShowCmd); with corresponding Unicode ShellExecuteW. If lpOperation is NULL, the default operation "open" is used; common values include "open", "print", or "explore". lpFile specifies the target file or URL; lpParameters and lpDirectory further customize the invocation; nShowCmd controls the window display state. The return value is an HINSTANCE; a value greater than 32 indicates success, while a value in the range of 0–32 indicates an error (e.g., file not found, access denied).

Usage notes: ShellExecute can launch a file with its associated program, start a URL or mailto, or execute a program with arguments. It relies on the system's file associations and the user's environment. It does not provide fine-grained process control and may present security risks if used with untrusted input.

Relation and alternatives: For more control and reliability, developers often prefer ShellExecuteEx or CreateProcess. ShellExecuteEx offers explicit security attributes, process handles, and better error reporting. ShellExecute remains in legacy code and is suitable for simple, one-shot operations.