95 строки
2.7 KiB
Plaintext
95 строки
2.7 KiB
Plaintext
.\" Copyright 2010 Cisco Systems, Inc. All rights reserved.
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.\" Copyright 2006-2008 Sun Microsystems, Inc.
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.\" Copyright (c) 1996 Thinking Machines Corporation
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.TH MPI_File_seek 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
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.SH NAME
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\fBMPI_File_seek\fP \- Updates individual file pointers (noncollective).
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.SH SYNTAX
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.ft R
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.nf
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C Syntax
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#include <mpi.h>
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int MPI_File_seek(MPI_File \fIfh\fP, MPI_Offset \fIoffset\fP,
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int \fIwhence\fP)
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.fi
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.SH Fortran Syntax (see FORTRAN 77 NOTES)
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.nf
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INCLUDE 'mpif.h'
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MPI_FILE_SEEK(\fIFH\fP,\fI OFFSET\fP,\fI WHENCE\fP,\fI IERROR\fP)
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INTEGER \fIFH, WHENCE, IERROR\fP
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INTEGER(KIND=MPI_OFFSET_KIND) \fIOFFSET\fP
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.fi
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.SH C++ Syntax
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.nf
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#include <mpi.h>
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void MPI::File::Seek(MPI::Offset \fIoffset\fP, int \fIwhence\fP)
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.fi
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.SH INPUT PARAMETERS
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.ft R
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.TP 1i
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fh
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File handle (handle).
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.TP 1i
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offset
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File offset (integer).
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.TP 1i
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whence
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Update mode (integer).
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.SH OUTPUT PARAMETER
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.ft R
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.TP 1i
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IERROR
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Fortran only: Error status (integer).
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.SH DESCRIPTION
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.ft R
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MPI_File_seek updates the individual file pointer according to
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.I whence,
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which could have the following possible values:
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.TP
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o
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MPI_SEEK_SET - The pointer is set to
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.I offset.
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.TP
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o
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MPI_SEEK_CUR - The pointer is set to the current pointer position plus
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.I offset.
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.TP
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o
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MPI_SEEK_END - The pointer is set to the end of the file plus
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.I offset.
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.sp
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.RE
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The
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.I offset
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can be negative, which allows seeking backwards. It is erroneous to
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seek to a negative position in the file. The end of the file is
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defined to be the location of the next elementary data item
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immediately after the last accessed data item, even if that location
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is a hole.
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.SH FORTRAN 77 NOTES
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.ft R
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The MPI standard prescribes portable Fortran syntax for
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the \fIOFFSET\fP argument only for Fortran 90. FORTRAN 77
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users may use the non-portable syntax
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.sp
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.nf
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INTEGER*MPI_OFFSET_KIND \fIOFFSET\fP
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.fi
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.sp
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where MPI_OFFSET_KIND is a constant defined in mpif.h
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and gives the length of the declared integer in bytes.
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.SH ERRORS
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Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.
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.sp
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Before the error value is returned, the current MPI error handler is
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called. For MPI I/O function errors, the default error handler is set to MPI_ERRORS_RETURN. The error handler may be changed with MPI_File_set_errhandler; the predefined error handler MPI_ERRORS_ARE_FATAL may be used to make I/O errors fatal. Note that MPI does not guarantee that an MPI program can continue past an error.
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