# 18.2.355. MPI_T_cvar_read

MPI_T_cvar_read — Read the value of a control variable

## 18.2.355.1. SYNTAX

### 18.2.355.1.1. C Syntax

    #include <mpi.h>

    int MPI_T_cvar_read(MPI_T_cvar_handle handle, const void *buf)

## 18.2.355.2. INPUT PARAMETERS

- `handle`: Handle of the control variable to be read.

- `buf`: Initial address of storage location for variable value.

## 18.2.355.3. DESCRIPTION

MPI_T_cvar_read reads the value of the control variable identified by the handle specified in handle and stores the value in the buffer pointed to by buf. The caller must ensure that the buffer pointed to by buf is large enough to hold the entire value of the control variable.

## 18.2.355.4. ERRORS

MPI_T_cvar_read will fail if:

- `MPI_T_ERR_NOT_INITIALIZED`: The MPI Tools interface not initialized

- `MPI_T_ERR_INVALID_HANDLE`: The handle is invalid

See also

- MPI_T_cvar_handle_alloc

- MPI_T_cvar_get_info