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.TH "MPI_COMM_C2F" "3" "Oct 18, 2026" "" "Open MPI"
.SH NAME
MPI_Comm_c2f \- UNKNOWN
.sp
MPI_Comm_f2c \%<#\:mpi-comm-f2c>, MPI_Comm_c2f,
MPI_Errhandler_f2c \%<#\:mpi-errhandler-f2c>, MPI_Errhandler_c2f \%<#\:mpi-errhandler-c2f>,
MPI_File_f2c \%<#\:mpi-file-f2c>, MPI_File_c2f \%<#\:mpi-file-c2f>,
MPI_Group_f2c \%<#\:mpi-group-f2c>, MPI_Group_c2f \%<#\:mpi-group-c2f>,
MPI_Info_f2c \%<#\:mpi-info-f2c>, MPI_Info_c2f \%<#\:mpi-info-c2f>,
MPI_Message_f2c \%<#\:mpi-message-f2c>, MPI_Message_c2f \%<#\:mpi-message-c2f>,
MPI_Op_f2c \%<#\:mpi-op-f2c>, MPI_Op_c2f \%<#\:mpi-op-c2f>,
MPI_Request_f2c \%<#\:mpi-request-f2c>, MPI_Request_c2f \%<#\:mpi-request-c2f>,
MPI_Session_f2c \%<#\:mpi-session-f2c>, MPI_Session_c2f \%<#\:mpi-session-c2f>,
MPI_Status_f2c \%<#\:mpi-status-f2c>, MPI_Status_c2f \%<#\:mpi-status-c2f>,
MPI_Type_f2c \%<#\:mpi-type-f2c>, MPI_Type_c2f \%<#\:mpi-type-c2f>,
MPI_Win_f2c \%<#\:mpi-win-f2c>, MPI_Win_c2f \%<#\:mpi-win-c2f> \- Translates a C handle into a Fortran
handle, or vice versa.
.SH DESCRIPTION
.sp
Handles are passed between Fortran and C by using an explicit C wrapper
to convert Fortran handles to C handles. There is no direct access to C
handles in Fortran. The type definition MPI_Fint is provided in C for
an integer of the size that matches a Fortran \fIINTEGER\fP; usually,
MPI_Fint will be equivalent to \fIint\fP\&. The handle translation functions
are provided in C to convert from a Fortran handle (which is an integer)
to a C handle, and vice versa.
.sp
For example, if \fIcomm\fP is a valid Fortran handle to a communicator, then
MPI_Comm_f2c \%<#\:mpi-comm-f2c> returns a valid C handle to that same communicator; if
\fIcomm\fP = MPI_COMM_NULL (Fortran value), then MPI_Comm_f2c \%<#\:mpi-comm-f2c> returns a null
C handle; if \fIcomm\fP is an invalid Fortran handle, then MPI_Comm_f2c \%<#\:mpi-comm-f2c>
returns an invalid C handle.
.SH NOTES
.sp
These functions are only available in C; they are not available in any
of the Fortran MPI interfaces.
.sp
This function does not return an error value. Consequently, the result
of calling it before MPI_Init \%<#\:mpi-init> or after MPI_Finalize \%<#\:mpi-finalize> is undefined.
.SH Author
The Open MPI community
.SH Copyright
2003-2026, The Open MPI Community
.\" End of generated man page.