MPI_INFO_ENV(3)					     Open MPI					   MPI_INFO_ENV(3)

MPI_Info_env — Static MPI_Info object containing info about the application

DESCRIPTION
       The  MPI-3  standard  established  a  static  MPI_Info object named MPI_Info_env that can be used to access
       information about how the application was executed from the run-time.

SUPPORTED FIELDS
       command
	      If available, the value will be set to argv[0]. Note that the value may not always  be  available	 -
	      e.g.,  it	 is  valid  for a program to call MPI_Init <#mpi-init> with NULL parameters, in which case
	      argv[0] will not be set if run as a singleton. This value will never be set in a Fortran program	as
	      the argv are not available.

       argv   The  argv	 given for the application. If no arguments are passed to the application, then this value
	      will not be set. It will also not be set in the case of a singleton that calls MPI_Init  <#mpi-init>
	      with NULL parameters, or a Fortran program.

       maxprocs
	      The number of processes in the job.

       soft   Open  MPI does not support the soft option for specifying the number of processes to be executed, so
	      this value is set to the same as maxprocs.

       host   The name of the host this process is executing upon - the value returned from gethostname().

       arch   The architecture of the host this process is executing upon. This	 value	indicates  the	underlying
	      chip architecture (e.g., x86_64), if it can be determined.

       wdir   The working directory at the time of process launch by mpiexec. Note that this value will not be set
	      for  processes  launched	as singletons as there is no reliable way for the MPI library to determine
	      the location.

       file   Although specified by the MPI-3 standard, no value is currently set for this field.

       thread_level
	      The requested MPI thread level - note that this may differ from the actual MPI thread level  of  the
	      application.

       ompi_num_apps
	      The number of application contexts in an MPMD job. This is an Open MPI-specific field and value.

       ompi_np
	      The number of processes in each application context, provided as a space-delimited list of integers.
	      This is an Open MPI-specific field and value.

       ompi_first_rank
	      The MPI rank of the first process in each application context, provided as a space-delimited list of
	      integers This is an Open MPI-specific field and value.

       ompi_positioned_file_dir
	      If Open MPI was asked to pre-position files, this field provides the top-level directory where those
	      files were place. This is an Open MPI-specific field and value.

ERRORS
       When calling MPI_Info_get <#mpi-info-get>, the flag parameter will be set to zero
       (false) if a value for the field has not been set.

       See also:

	  • MPI_Info_get <#mpi-info-get>

Copyright
       2003-2026, The Open MPI Community

						   Mar 05, 2026					   MPI_INFO_ENV(3)
