=head1 NAME

getas - execute a command and reveive its translated stdout

=head1 SYNOPSIS

  getas(command, [Options...])
 

=head1 DESCRIPTION

This funcion execute C<command>, reads its output and translate it acording
the options received (using the external PERL command C<any2sexp>.

By default the standard output of the command is tranlated to a C<STR-seq>
(the seq of the lines).

The external command C<any2sexp> (that can be enriched if we want) knows
about tables C<STR-seq-seq>:

  getas("ps", 
        ['type -> "tab", 
         'fs   -> "...fieldseparator", 
         'rs   -> "...registerSeparator"])

As soon as you have it in camila, you can build a function to translate
the values to a more suitable model if necessary.

=head1 Examples

Listing currend directory:

   pp(getas("ls -1",[]));

Reading date and time:

   pp(getas("date +'%m %d %H %M %S'", [ 'type -> 'txt, 'rs -> " "]));

Process status:

   pp(getas("ps", ['type -> 'tab]));

Which files use C<getas>:

   pp(getas("grep getas *.cam", ['type -> 'tab, 'fs -> ":"]));

=cut

func getas(com,o)
; o is a mapping with command and options
; Example getas("cat /etc/passwd", ['type-> "tab", 'fs ->":"]);
;  options = the options available in "any2sexp" command
;     Ex 'type : ("txt" | "tab" )
;        'F    : STR          Field separator
;        'R    : STR          register separator
returns
  let(comm= com ++ " | any2sexp " ++
        strcat-red("",
           <" -" ++ tostr(x) ++ "=\"" ++ tostr(o[x]) ++ "\""| x <- dom(o)>),
      a = popen(comm,"r"),
      b = readf(a),
        = pclose(a)) in b;

tostr(x)=if( is-STR(x) -> x,
             is-SYM(x) -> symstr(x),
             is-INT(x) -> itoa(x));