.TH MPI_File_read_all_begin 3 "2/8/2024" " " "MPI" .SH NAME MPI_File_read_all_begin \- Begin a split collective read using individual file pointer .SH SYNOPSIS .nf int MPI_File_read_all_begin(MPI_File fh, void *buf, int count, MPI_Datatype datatype) .fi .SH INPUT PARAMETERS .PD 0 .TP .B fh - file handle (handle) .PD 1 .PD 0 .TP .B count - number of elements in buffer (nonnegative integer) .PD 1 .PD 0 .TP .B datatype - datatype of each buffer element (handle) .PD 1 .SH OUTPUT PARAMETERS .PD 0 .TP .B buf - initial address of buffer (choice) .PD 1 .SH NOTES FOR FORTRAN All MPI routines in Fortran (except for .I MPI_WTIME and .I MPI_WTICK ) have an additional argument .I ierr at the end of the argument list. .I ierr is an integer and has the same meaning as the return value of the routine in C. In Fortran, MPI routines are subroutines, and are invoked with the .I call statement. All MPI objects (e.g., .I MPI_Datatype , .I MPI_Comm ) are of type .I INTEGER in Fortran.