---
name: "erl_global"
section: "3erl"
platform: "linux"
package: "erlang-manpages"
version: "1:21.2.6+dfsg-1"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/erl_global"
---

# erl\_global(3erl)

Access globally registered names.

## NAME

erl\_global - Access globally registered names.

## DESCRIPTION

This module provides support for registering, looking up, and unregistering names in the *global* module. For more information, see *kernel:global*.

Notice that the functions below perform an RPC using an open file descriptor provided by the caller. This file descriptor must not be used for other traffic during the global operation, as the function can then receive unexpected data and fail.

## EXPORTS

**char \*\*erl\_global\_names(fd,count)**\

Types:

int fd;\
 int \*count;\

Retrieves a list of all known global names.

- \*

  *fd* is an open descriptor to an Erlang connection.

- \*

  *count* is the address of an integer, or *NULL*. If *count* is not *NULL*, it is set by the function to the number of names found.

On success, the function returns an array of strings, each containing a single registered name, and sets *count* to the number of names found. The array is terminated by a single *NULL* pointer. On failure, the function returns *NULL* and *count* is not modified.

**Note:**

It is the caller's responsibility to free the array afterwards. It has been allocated by the function with a single call to *malloc()*, so a single *free()* is all that is necessary.

**int erl\_global\_register(fd,name,pid)**\

Types:

int fd;\
 const char \*name;\
 ETERM \*pid;\

Registers a name in *global*.

- \*

  *fd* is an open descriptor to an Erlang connection.

- \*

  *name* is the name to register in *global*.

- \*

  *pid* is the pid that is to be associated with *name*. This value is returned by *global* when processes request the location of *name*.

Returns *0* on success, otherwise *-1*.

**int erl\_global\_unregister(fd,name)**\

Types:

int fd;\
 const char \*name;\

Unregisters a name from *global*.

- \*

  *fd* is an open descriptor to an Erlang connection.

- \*

  *name* is the name to unregister from *global*.

Returns *0* on success, otherwise *-1*.

**ETERM \*erl\_global\_whereis(fd,name,node)**\

Types:

int fd;\
 const char \*name;\
 char \*node;\

Looks up a name in *global*.

- \*

  *fd* is an open descriptor to an Erlang connection.

- \*

  *name* is the name that is to be looked up in *global*.

If *node* is not *NULL*, it is a pointer to a buffer where the function can fill in the name of the node where *name* is found. *node* can be passed directly to *erl\_connect()* if necessary.

On success, the function returns an Erlang pid containing the address of the specified name, and the node is initialized to the node name where *name* is found. On failure, *NULL* is returned and *node* is not modified.