---
name: "MPI_T_cvar_read"
section: "3"
platform: "linux"
package: "openmpi"
version: "5.0.11-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/MPI_T_cvar_read"
---

# MPI\_T\_cvar\_read(3)

*MPI\_T\_cvar\_read* — Read the value of a control variable

## SYNTAX

### C Syntax

```
#include <mpi.h>
int MPI_T_cvar_read(MPI_T_cvar_handle handle, const void *buf)
```

## INPUT PARAMETERS

- •

  **handle**: Handle of the control variable to be read.

- •

  **buf**: Initial address of storage location for variable value.

## 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.

## 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*

## COPYRIGHT

2003-2026, The Open MPI Community