# MPI_T_category_get_info

Get the information about a category

## Synopsis

    int MPI_T_category_get_info(int cat_index, char *name, int *name_len, char *desc,
            int *desc_len, int *num_cvars, int *num_pvars, int *num_categories)

## Input/Output Parameters

name_len
  length of the string and/or buffer for name (integer)
desc_len
  length of the string and/or buffer for desc (integer)

## Input Parameters

cat_index
  index of the category to be queried (integer)

## Output Parameters

name
  buffer to return the string containing the name of the category (string)
desc
  buffer to return the string containing the description of the category (string)
num_cvars
  number of control variables contained in the category (integer)
num_pvars
  number of performance variables contained in the category (integer)
num_categories
  number of categories contained in the category (integer)

## Thread and Interrupt Safety

This routine is thread-safe. This means that this routine may be safely used by multiple threads without the need for any user-provided thread locks. However, the routine is not interrupt safe. Typically, this is due to the use of memory allocation routines such as `malloc` or other non-MPICH runtime routines that are themselves not interrupt-safe.

## Errors

All MPI routines (except `MPI_Wtime` and `MPI_Wtick`) return an error value; C routines as the value of the function and Fortran routines in the last argument. Before the value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job. The error handler may be changed with `MPI_Comm_set_errhandler` (for communicators), `MPI_File_set_errhandler` (for files), and `MPI_Win_set_errhandler` (for RMA windows). The MPI-1 routine `MPI_Errhandler_set` may be used but its use is deprecated. The predefined error handler `MPI_ERRORS_RETURN` may be used to cause error values to be returned. Note that MPI does not guarentee that an MPI program can continue past an error; however, MPI implementations will attempt to continue whenever possible.

MPI_SUCCESS
  No error; MPI routine completed successfully.

MPI_T_ERR_NOT_INITIALIZED
  The MPI tool information interface is not initialized.

MPI_T_ERR_INVALID_INDEX
  Index is invalid or has been deleted.