This topic has not yet been rated - Rate this topic

_spawnvp, _wspawnvp

Visual Studio 2012

Creates a process and executes it.

Important
This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.

intptr_t _spawnvp(
   int mode,
   const char *cmdname,
   const char *const *argv 
);
intptr_t _wspawnvp(
   int mode,
   const wchar_t *cmdname,
   const wchar_t *const *argv 
);

Parameters

mode: Execution mode for calling the process.
cmdname: Path of the file to be executed.
argv: Array of pointers to arguments. The argument argv[0] is usually a pointer to a path in real mode or to the program name in protected mode, and argv[1] through argv[n] are pointers to the character strings that form the new argument list. The argument argv[n +1] must be a NULL pointer to mark the end of the argument list.

Return Value

The return value from a synchronous _spawnvp or _wspawnvp (_P_WAIT specified for mode) is the exit status of the new process. The return value from an asynchronous _spawnvp or _wspawnvp (_P_NOWAIT or _P_NOWAITO specified for mode) is the process handle. The exit status is 0 if the process terminated normally. You can set the exit status to a nonzero value if the spawned process specifically uses a nonzero argument to call the exit routine. If the new process did not explicitly set a positive exit status, a positive exit status indicates an abnormal exit with an abort or an interrupt. A return value of –1 indicates an error (the new process is not started). In this case, errno is set to one of the following values:

E2BIG: Argument list exceeds 1024 bytes.
EINVAL: mode argument is invalid.
ENOENT: File or path is not found.
ENOEXEC: Specified file is not executable or has invalid executable-file format.
ENOMEM: Not enough memory is available to execute the new process.

For more information about these, and other, return codes, see errno, _doserrno, _sys_errlist, and _sys_nerr.

Remarks

Each of these functions creates a new process and executes it, and passes an array of pointers to command-line arguments and uses the PATH environment variable to find the file to execute.

These functions validate their parameters. If either cmdname or argv is a null pointer, or if argv points to null pointer, or argv[0] is an empty string, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, these functions set errno to EINVAL, and return -1. No new process is spawned.