_spawnlp, _wspawnlp
Collapse the table of content
Expand the table of content
Important This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here. ArchiveDisclaimer

_spawnlp, _wspawnlp

Creates and executes a new process.

intptr_t _spawnlp(
   int mode,
   const char *cmdname,
   const char *arg0,
   const char *arg1,
   ... const char *argn,
intptr_t _wspawnlp(
   int mode,
   const wchar_t *cmdname,
   const wchar_t *arg0,
   const wchar_t *arg1,
   ... const wchar_t *argn,


Execution mode for the calling process.


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.

The return value from a synchronous _spawnlp or _wspawnlp (_P_WAIT specified for mode) is the exit status of the new process. The return value from an asynchronous _spawnlp or _wspawnlp (_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.


Argument list exceeds 1024 bytes.


mode argument is invalid.


File or path is not found.


Specified file is not executable or has invalid executable-file format.


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.

Each of these functions creates and executes a new process, passing each command-line argument as a separate parameter and using 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, these functions generate an invalid parameter exception, 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.


Required header




<stdio.h> or <wchar.h>

For more compatibility information, see Compatibility in the Introduction.

© 2015 Microsoft