Provided by: erlang-base_16.b.3-dfsg-1ubuntu2_amd64 bug

NAME

       erl_call - Call/Start a Distributed Erlang Node

DESCRIPTION

       erl_call  makes it possible to start and/or communicate with a distributed Erlang node. It
       is built upon the erl_interface library as an example application. Its purpose is  to  use
       an  Unix  shell  script  to  interact  with  a  distributed  Erlang  node. It performs all
       communication with the Erlang rex server, using the standard Erlang RPC facility. It  does
       not require any special software to be run at the Erlang target node.

       The  main use is to either start a distributed Erlang node or to make an ordinary function
       call. However, it is also possible to pipe an  Erlang  module  to  erl_call  and  have  it
       compiled,  or  to  pipe  a  sequence of Erlang expressions to be evaluated (similar to the
       Erlang shell).

       Options, which cause stdin to be read, can be used with advantage as scripts  from  within
       (Unix) shell scripts. Another nice use of erl_call could be from (http) CGI-bin scripts.

EXPORTS

       erl_call <options>

              Each option flag is described below with its name, type and meaning.

                -a [Mod [Fun [Args]]]]:
                  (optional):  Applies the specified function and returns the result. Mod must be
                  specified, however start and [] are  assumed  for  unspecified  Fun  and  Args,
                  respectively.  Args  should  be  in the same format as for erlang:apply/3. Note
                  that this flag takes exactly one argument, so quoting may be necessary in order
                  to  group  Mod,  Fun  and  Args,  in a manner dependent on the behavior of your
                  command shell.

                -c Cookie:
                  (optional): Use this option to specify  a  certain  cookie.  If  no  cookie  is
                  specified,  the  ~/.erlang.cookie  file  is  read  and  its content are used as
                  cookie. The Erlang node we want to communicate with must have the same cookie.

                -d:
                  (optional):  Debug  mode.  This  causes  all  IO  to  be  output  to  the  file
                  ~/.erl_call.out.Nodename, where Nodename is the node name of the Erlang node in
                  question.

                -e:
                  (optional): Reads a sequence of Erlang expressions, separated by ',' and  ended
                  with  a  '.',  from  stdin until EOF (Control-D). Evaluates the expressions and
                  returns the result from the last expression. Returns {ok,Result} if successful.

                -h HiddenName:
                  (optional): Specifies the name of the hidden node that erl_call represents.

                -m:
                  (optional): Reads an Erlang module from stdin and compiles it.

                -n Node:
                  (one of -n, -name, -sname is required): Has the same meaning as -name  and  can
                  still be used for backwards compatibility reasons.

                -name Node:
                  (one  of  -n,  -name,  -sname  is required): Node is the name of the node to be
                  started or communicated with. It is assumed  that  Node  is  started  with  erl
                  -name,  which  means  that  fully qualified long node names are used. If the -s
                  option is given, an Erlang node will (if necessary) be started with erl -name.

                -q:
                  (optional): Halts the Erlang node specified with the  -n  switch.  This  switch
                  overrides the -s switch.

                -r:
                  (optional):   Generates  a  random  name  of  the  hidden  node  that  erl_call
                  represents.

                -s:
                  (optional): Starts a distributed Erlang node if necessary. This means that in a
                  sequence  of  calls,  where the '-s' and '-n Node' are constant, only the first
                  call will start the Erlang node. This makes the rest of the communication  very
                  fast. This flag is currently only available on the Unix platform.

                -sname Node:
                  (one  of  -n,  -name,  -sname  is required): Node is the name of the node to be
                  started or communicated with. It is assumed  that  Node  is  started  with  erl
                  -sname  which  means  that short node names are used. If -s option is given, an
                  Erlang node will be started (if necessary) with erl -sname.

                -v:
                  (optional): Prints a lot of verbose information. This is only  useful  for  the
                  developer and maintainer of erl_call.

                -x ErlScript:
                  (optional): Specifies another name of the Erlang start-up script to be used. If
                  not specified, the standard erl start-up script is used.

EXAMPLES

       Starts an Erlang node and calls erlang:time/0.

       erl_call -s -a 'erlang time' -n madonna
       {18,27,34}

       Terminates an Erlang node by calling erlang:halt/0.

       erl_call -s -a 'erlang halt' -n madonna

       An apply with several arguments.

       erl_call -s -a 'lists map [{math,sqrt},[1,4,9,16,25]]' -n madonna

       Evaluates a couple of expressions. The input ends with EOF (Control-D) .

       erl_call -s -e -n madonna
       statistics(runtime),
       X=1,
       Y=2,
       {_,T}=statistics(runtime),
       {X+Y,T}.
       ^D
       {ok,{3,0}}

       Compiles a module and runs it. Again, the input  ends  with  EOF  (Control-D)  .  (In  the
       example shown, the output has been formatted afterwards).

       erl_call -s -m -a lolita -n madonna
       -module(lolita).
       -compile(export_all).
       start() ->
               P = processes(),
               F = fun(X) -> {X,process_info(X,registered_name)} end,
               lists:map(F,[],P).
       ^D
       [{<madonna@chivas.du.etx.ericsson.se,0,0>,
                         {registered_name,init}},
        {<madonna@chivas.du.etx.ericsson.se,2,0>,
                         {registered_name,erl_prim_loader}},
        {<madonna@chivas.du.etx.ericsson.se,4,0>,
                         {registered_name,error_logger}},
        {<madonna@chivas.du.etx.ericsson.se,5,0>,
                         {registered_name,application_controller}},
        {<madonna@chivas.du.etx.ericsson.se,6,0>,
                         {registered_name,kernel}},
        {<madonna@chivas.du.etx.ericsson.se,7,0>,
                         []},
        {<madonna@chivas.du.etx.ericsson.se,8,0>,
                         {registered_name,kernel_sup}},
        {<madonna@chivas.du.etx.ericsson.se,9,0>,
                         {registered_name,net_sup}},
        {<madonna@chivas.du.etx.ericsson.se,10,0>,
                         {registered_name,net_kernel}},
        {<madonna@chivas.du.etx.ericsson.se,11,0>,
                         []},
        {<madonna@chivas.du.etx.ericsson.se,12,0>,
                         {registered_name,global_name_server}},
        {<madonna@chivas.du.etx.ericsson.se,13,0>,
                         {registered_name,auth}},
        {<madonna@chivas.du.etx.ericsson.se,14,0>,
                         {registered_name,rex}},
        {<madonna@chivas.du.etx.ericsson.se,15,0>,
                         []},
        {<madonna@chivas.du.etx.ericsson.se,16,0>,
                         {registered_name,file_server}},
        {<madonna@chivas.du.etx.ericsson.se,17,0>,
                         {registered_name,code_server}},
        {<madonna@chivas.du.etx.ericsson.se,20,0>,
                         {registered_name,user}},
        {<madonna@chivas.du.etx.ericsson.se,38,0>,
                         []}]