# $Id$

A daemon for mapping Unix shell commands to XML-RPC functions.

NOTE: you need to configure these defaults:

  SxRegistryComponentUser
  SxRegistryComponentPassword

on NSGlobalDomain to make registration of other services work.

How it works
============

A unix command is very similiar to an XML-RPC function, it
has input parameters, it has a result and it has a name.
Additionally a unix command has input, output and error streams
as well as possible input and output files. All the IO
options of an Unix command need to be mapped to XML-RPC
parameters and results.

Sample: mapping the Unix find command
=====================================

Find takes it's parameters on the command line and delivers
the result on the stdout stream. Error codes are returned
using the exit status and error messages on the stderr
stream.

Unix call:
  find / -name "*a*" -type d

XML-RPC Function:
  Array com.skyrix.system.find(String root, name, type)

Mapper:
  com.skyrix.system.find = {
    executable = "/usr/bin/find";
    signatures = {
      ( String )         = { cmdline = "$0"; };
      ( String, String ) = { cmdline = "$0 -name $1"; };
      ( String, String, String ) = { cmdline = "$0 -name $1 -type $2"; };
    };
    result = {
      value   = "<STDOUT>";
      type    = "arrayOfLines";
    };
    fault = {
      code    = "$$";
      message = "<STDERR>";
    };
  };

Sample: mapping the Unix eval command
=====================================

Unix call:
  echo "1+2/3" | bc

XML-RPC Function:
  Object com.skyrix.system.bc(String statements)
  Object com.skyrix.system.bc(i4 a, i4 b)

Mapper:
  com.skyrix.system.bc = {
    executable = "/usr/bin/bc";
    signatures = {
      ( String ) = { stdin="$0\n";        };
      ( i4, i4 ) = { stdin="$0$ + $1$\n"; };
    };
    result = {
      value   = "<STDOUT>";
      type    = "string";
    };
    fault = {
      code    = "$$";
      message = "<STDERR>";
    };
  };