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

# shmem\_ptr(3)

[*shmem\_ptr*(3)](/shmem_ptr/3.md) - Returns a pointer to a data object on a specified processing element (PE).

## SYNOPSIS

C or C++:

```
#include <mpp/shmem.h>
void *shmem_ptr(const void *target, int pe)
```

Fortran:

```
INCLUDE "mpp/shmem.fh"
POINTER (PTR, POINTEE)
INTEGER pe
PTR = SHMEM_PTR(target, pe)
```

## DESCRIPTION

The *shmem\_ptr* routine returns an address that can be used to directly reference **target** on the remote PE **pe**. With this address we can perform ordinary loads and stores to the remote address.

When a sequence of loads (gets) and stores (puts) to a data object on a remote PE does not match the access pattern provided in a SHMEM data transfer routine like [*shmem\_put32*(3)](/shmem_put32/3.md) or shmem\_real\_iget(3), the *shmem\_ptr* function can provide an efficient means to accomplish the communication.

The arguments are as follows:

- **target**

  The symmetric data object to be referenced.

- **pe**

  An integer that indicates the PE number on which target is to be accessed. If you are using Fortran, it must be a default integer value.

## EXAMPLES

This Fortran program calls *shmem\_ptr* and then PE 0 writes to the BIGD array on PE 1:

```
PROGRAM REMOTEWRITE
  INCLUDE 'mpp/shmem.fh'
  INTEGER BIGD(100)
  SAVE BIGD
  INTEGER POINTEE(*)
  POINTER (PTR,POINTEE)
  CALL START_PES(0)
  IF (MY_PE() .EQ. 0) THEN
                             ! initialize PE 1's BIGD array
    PTR = SHMEM_PTR(BIGD, 1) ! get address of PE 1's BIGD
                             ! array
    DO I=1,100
      POINTEE(I) = I
    ENDDO
  ENDIF
  CALL SHMEM_BARRIER_ALL
  IF (MY_PE() .EQ. 1) THEN
    PRINT *, 'BIGD on PE 1 is: '
    PRINT *, BIGD
  ENDIF
END
```

This is the equivalent program written in C:

```
#include <mpp/shmem.h>
main()
{
  static int bigd[100];
  int *ptr;
  int i;
  shmem_init();
  if (shmem_my_pe() == 0) {
  /* initialize PE 1's bigd array */
    ptr = shmem_ptr(bigd, 1);
    for (i=0; i<100; i++)
      *ptr++ = i+1;
  }
  shmem_barrier_all();
  if (shmem_my_pe() == 1) {
    printf("bigd on PE 1 is:\n");
    for (i=0; i<100; i++)
      printf(" %d\n",bigd[i]);
    printf("\n");
  }
}
```

## NOTES

The *shmem\_ptr* function is available only on systems where ordinary memory loads and stores are used to implement SHMEM put and get operations.

## RETURN VALUES

*shmem\_ptr* returns a pointer to the data object on the specified remote PE. If target is not remotely accessible, a NULL pointer is returned.

**SEE ALSO:**

[*intro\_shmem*(3)](/intro_shmem/3.md) *shmem\_put*(3) *shmem\_get*(3)

## COPYRIGHT

2003-2026, The Open MPI Community