_spawnlpe, _wspawnlpe

مقالة
06/30/2010

Creates and executes a new process.

intptr_t _spawnlpe(
   int mode,
   const char *cmdname,
   const char *arg0,
   const char *arg1,
   ...  const char *argn,
   NULL,
   const char *const *envp 
);
intptr_t _wspawnlpe(
   int mode,
   const wchar_t *cmdname,
   const wchar_t *arg0,
   const wchar_t *arg1,
   ...  const wchar_t *argn,
   NULL,
   const wchar_t *const *envp 
);

Parámetros

mode
Execution mode for the calling process.
cmdname
Path of the file to be executed.
arg0, arg1, ...argn
List of pointers to arguments. The arg0 argument is usually a pointer to cmdname. The arguments arg1 through argn are pointers to the character strings forming the new argument list. Following argn, there must be a NULL pointer to mark the end of the argument list.
envp
Array of pointers to environment settings.

Valor devuelto

The return value from a synchronous _spawnlpe or _wspawnlpe (_P_WAIT specified for mode) is the exit status of the new process. The return value from an asynchronous _spawnlpe or _wspawnlpe (_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 calls the exit routine with a nonzero argument. 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 _doserrno, errno, _sys_errlist, and _sys_nerr.

Comentarios

Each of these functions creates and executes a new process, passing each command-line argument as a separate parameter and passing an array of pointers to environment settings. These functions use the PATH environment variable to find the file to execute.

These functions validate their parameters. If either cmdname or arg0 is an empty string or a null pointer, 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.