File IO

C | Fortran-2008 | Fortran-90

MPI_File

Definition

MPI_File represents a file handle in MPI, it is used in MPI IO routines such as MPI_File_open for instance.

Example

Copy

Feedback

#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>

/**
 * @brief Illustrates the use of the MPI_File handle.
 * @details This applications consists in opening a file in read-write mode, or
 * create it if it does not already exist, and get a handle on that file.
 **/
int main(int argc, char* argv[])
{
    MPI_Init(&argc, &argv);

    int my_rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);

    MPI_File handle;
    int access_mode = MPI_MODE_CREATE /* Create the file if it does not exist */
                    | MPI_MODE_RDWR; /* With read-write access */
    if(MPI_File_open(MPI_COMM_WORLD, "file.tmp", access_mode, MPI_INFO_NULL, &handle) != MPI_SUCCESS)
    {
        printf("[MPI process %d] Failure in opening the file.\n", my_rank);
        MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);
    }

    printf("[MPI process %d] File opened successfully.\n", my_rank);

    if(MPI_File_close(&handle) != MPI_SUCCESS)
    {
        printf("[MPI process %d] Failure in closing the file.\n", my_rank);
        MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);
    }

    printf("[MPI process %d] File closed successfully.\n", my_rank);

    MPI_Finalize();

    return EXIT_SUCCESS;
}