MPI_File_seek

MPI_File_seek is a function in the C++ programming language that allows the user to set the current position of the file handle associated with an MPI-parallel file. The function takes three parameters: the file handle, the offset, and the position.

The file handle parameter is an object that represents the file being accessed. It is obtained using the MPI_File_open function.

The offset parameter specifies the displacement (in bytes) from the position specified by the position parameter. It can be a positive or negative value.

The position parameter determines the reference position used for seeking. It can take on the following values:

• MPI_SEEK_SET: The reference position is the beginning of the file.
• MPI_SEEK_CUR: The reference position is the current position of the file handle.
• MPI_SEEK_END: The reference position is the end of the file.

After the MPI_File_seek function is called, the current position of the file handle is set according to the specified offset and position. This allows the user to read or write data from or to a specific location in the file.

It's important to note that the MPI_File_seek function operates in a collective manner, meaning that all processes in the communicator associated with the file handle must call the function with the same parameters. Additionally, the file handle must have been opened in a mode that supports positioning, such as MPI_MODE_SEQUENTIAL or MPI_MODE_RDWR.

Overall, the MPI_File_seek function is a useful tool for navigating through parallel files in C++ using the MPI library.