1########################################################################
2##
3## Copyright (C) %!-2019 The Octave Project Developers
4##
5## See the file COPYRIGHT.md in the top-level directory of this
6## distribution or <https://octave.org/copyright/>.
7##
8## This file is part of Octave.
9##
10## Octave is free software: you can redistribute it and/or modify it
11## under the terms of the GNU General Public License as published by
12## the Free Software Foundation, either version 3 of the License, or
13## (at your option) any later version.
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15## Octave is distributed in the hope that it will be useful, but
16## WITHOUT ANY WARRANTY; without even the implied warranty of
17## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18## GNU General Public License for more details.
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20## You should have received a copy of the GNU General Public License
21## along with Octave; see the file COPYING.  If not, see
22## <https://www.gnu.org/licenses/>.
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24########################################################################
25
26## -*- texinfo -*-
27## @deftypefn  {} {} type @var{name} @dots{}
28## @deftypefnx {} {} type -q @var{name} @dots{}
29## @deftypefnx {} {text =} type ("@var{name}", @dots{})
30## Display the contents of @var{name} which may be a file, function (m-file),
31## variable, operator, or keyword.
32##
33## @code{type} normally prepends a header line describing the category of
34## @var{name} such as function or variable; The @option{-q} option suppresses
35## this behavior.
36##
37## If no output variable is used the contents are displayed on screen.
38## Otherwise, a cell array of strings is returned, where each element
39## corresponds to the contents of each requested function.
40## @end deftypefn
41
42function text = type (varargin)
43
44  if (nargin == 0)
45    print_usage ();
46  elseif (! iscellstr (varargin))
47    error ("type: input arguments must be strings");
48  endif
49
50  quiet = false;
51  idx = strcmpi (varargin, "-q") | strcmpi (varargin, "-quiet");
52  if (any (idx))
53    quiet = true;
54    varargin(idx) = [];
55  endif
56
57  if (nargout > 0)
58    text = cell (size (varargin));
59  endif
60
61  for n = 1:length (varargin)
62    name = varargin{n};
63
64    ## Find function and get its code
65    txt = "";
66    cmd = sprintf ("exist ('%s')", name);
67    e = evalin ("caller", cmd);
68    if (e == 1)
69      ## Variable
70      cmd = sprintf ("disp (%s);", name);
71      desc = evalin ("caller", cmd);
72      if (quiet)
73        txt = desc;
74      else
75        txt = sprintf ("%s is a variable\n%s", name, desc);
76      endif
77    elseif (e == 2)
78      ## m-file or ordinary file
79      file = which (name);
80      if (length (file) > 2)
81        ext = file(end-1:end);
82      endif
83      if (isempty (file) || ! strcmpi (ext, ".m"))
84        ## 'name' is an ordinary file, and not a function name.
85        file = file_in_loadpath (name);
86        quiet = true;
87      endif
88
89      ## Read the file
90      fid = fopen (file, "r");
91      if (fid < 0)
92        error ("type: couldn't open '%s' for reading", file);
93      endif
94      contents = char (fread (fid).');
95      fclose (fid);
96
97      if (quiet)
98        txt = contents;
99      else
100        txt = sprintf ("%s is the user-defined function defined from: %s\n\n%s",
101                        name, file, contents);
102      endif
103    elseif (e == 3)
104      txt = sprintf ("%s is a dynamically-linked function", name);
105    elseif (e == 5)
106      txt = sprintf ("%s is a built-in function", name);
107    elseif (e == 103)
108      contents = __get_cmdline_fcn_txt__ (name);
109      if (isempty (contents))
110        txt = sprintf ("%s is a command-line function with no definition",
111                       name);
112      else
113        if (quiet)
114          txt = contents;
115        else
116          txt = sprintf ("%s is the command-line function:\n\n%s",
117                         name, contents);
118        endif
119      endif
120    elseif (any (strcmp (__operators__ (), name)))
121      txt = sprintf ("%s is an operator", name);
122    elseif (any (strcmp (__keywords__ (), name)))
123      txt = sprintf ("%s is a keyword", name);
124    else
125      error ("type: '%s' undefined\n", name);
126    endif
127
128    if (nargout == 0)
129      disp (txt);
130    else
131      text{n} = txt;
132    endif
133  endfor
134
135endfunction
136
137
138%!test
139%! var = 1;
140%! txt = type ("var");
141%! typestr = txt{1}(1:17);
142%! assert (typestr, "var is a variable");
143
144%!test
145%! txt = type ("ls");
146%! typestr = txt{1}(1:31);
147%! assert (typestr, "ls is the user-defined function");
148
149%!test
150%! txt = type ("ls", "-q");
151%! assert (regexp (txt{1}, '[#\s]*Copyright \(C\) 2006'));
152
153%!assert (type ("fftw"){1}, "fftw is a dynamically-linked function")
154%!assert (type ("cat"){1}, "cat is a built-in function")
155%!assert (type ("+"){1}, "+ is an operator")
156%!assert (type ("end"){1}, "end is a keyword")
157
158%!error type ()
159%!error <'__NO_NAME__' undefined> type ('__NO_NAME__')
160