1ei_global(3)                  C Library Functions                 ei_global(3)
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3
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NAME

6       ei_global - Access globally registered names.
7

DESCRIPTION

9       This  module provides support for registering, looking up, and unregis‐
10       tering names in the global  module.  For  more  information,  see  ker‐
11       nel:global.
12
13       Notice  that  the functions below perform an RPC using an open file de‐
14       scriptor provided by the caller. This file descriptor must not be  used
15       for other traffic during the global operation, as the function can then
16       receive unexpected data and fail.
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EXPORTS

19       char **ei_global_names(ec,fd,count)
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21              Types:
22
23                 ei_cnode *ec;
24                 int fd;
25                 int *count;
26
27              Retrieves a list of all known global names.
28
29                * ec is the ei_cnode representing the current cnode.
30
31                * fd is an open descriptor to an Erlang connection.
32
33                * count is the address of an integer, or NULL. If count is not
34                  NULL,  it  is  set  by  the  function to the number of names
35                  found.
36
37              On success, the function returns an array of strings, each  con‐
38              taining  a  single registered name, and sets count to the number
39              of names found.  The  array  is  terminated  by  a  single  NULL
40              pointer.  On failure, the function returns NULL and count is not
41              modified.
42
43          Note:
44              It is the caller's responsibility to free the array  afterwards.
45              It has been allocated by the function with a single call to mal‐
46              loc(), so a single free() is all that is necessary.
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48
49       int ei_global_register(fd,name,pid)
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51              Types:
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53                 int fd;
54                 const char *name;
55                 erlang_pid *pid;
56
57              Registers a name in global.
58
59                * fd is an open descriptor to an Erlang connection.
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61                * name is the name to register in global.
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63                * pid is the pid that is to  be  associated  with  name.  This
64                  value is returned by global when processes request the loca‐
65                  tion of name.
66
67              Returns 0 on success, otherwise -1.
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69       int ei_global_unregister(ec,fd,name)
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71              Types:
72
73                 ei_cnode *ec;
74                 int fd;
75                 const char *name;
76
77              Unregisters a name from global.
78
79                * ec is the ei_cnode representing the current cnode.
80
81                * fd is an open descriptor to an Erlang connection.
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83                * name is the name to unregister from global.
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85              Returns 0 on success, otherwise -1.
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87       int ei_global_whereis(ec,fd,name,pid,node)
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89              Types:
90
91                 ei_cnode *ec;
92                 int fd;
93                 const char *name;
94                 erlang_pid *pid;
95                 char *node;
96
97              Looks up a name in global.
98
99                * ec is the ei_cnode representing the current cnode.
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101                * fd is an open descriptor to an Erlang connection.
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103                * name is the name that is to be looked up in global.
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105              The pid parameter is a pointer to a erlang_pid that the function
106              will  update  with  the  pid associated with the global name, if
107              successful.
108
109              If node is not NULL, it is a pointer to a buffer where the func‐
110              tion  can fill in the name of the node where name is found. node
111              can be passed directly to ei_connect() if necessary.
112
113              On success, the  function  returns  0,  updates  the  erlang_pid
114              pointed  to by the pid parameter, and the node parameter is ini‐
115              tialized to the node name where name is  found.  On  failure,  a
116              negative number is returned.
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120Ericsson AB                   erl_interface 5.2.2                 ei_global(3)