## nn_reallocmsg

Reallocate message (compatible API).

### Synopsis

```c
#include <nanomsg/nn.h>

void *nn_reallocmsg(void *old, size_t size);
```

### Description

The `nn_reallocmsg` reallocates the message _old_, making it of size _size_.

On success, the contents of _old_ are copied into the new message (truncating if appropriate), then _old_ is deallocated, and a pointer to the new message payload is returned.

On failure, the _old_ message is unchanged, and the value `NULL` is returnedto the caller.

### Return Values

This function returns a pointer to message buffer space, or `NULL` on failure.

### Errors

[horizontal]
`ENOMEM`:: Insufficient memory is available.
`EINVAL`:: An invalid _size_ was specified.
`ETERM`:: The library is shutting down.

### See Also

xref:nn_allocmsg.adoc[nn_allocmsg],
xref:nn_freemsg.adoc[nn_freemsg],
xref:nn_errno.adoc[nn_errno]