Expose getopt:tokenize/1 and command-line literals

zsolt-erl · Jul 20, 2012 · f55ef18 · f55ef18
1 parent 08931e2
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diff --git a/README.md b/README.md
@@ -39,6 +39,8 @@ The *getopt* module provides four functions:
 parse([{Name, Short, Long, ArgSpec, Help}], Args :: string() | [string()]) ->
     {ok, {Options, NonOptionArgs}} | {error, {Reason, Data}}
 
+tokenize(CmdLine :: string()) -> [string()]
+
 usage([{Name, Short, Long, ArgSpec, Help}], ProgramName :: string()) -> ok
 
 usage([{Name, Short, Long, ArgSpec, Help}], ProgramName :: string(),
@@ -137,6 +139,21 @@ Will return:
      ["dummy1","dummy2"]}}
 ```
 
+The ``tokenize/1`` function will separate a command line string into
+tokens, taking into account whether an argument is single or double
+quoted, a character is escaped or there are environment variables to
+be expanded. e.g.:
+
+``` erlang
+getopt:tokenize("  --name John\\ Smith --path \"John's Files\" -u ${USER}").
+```
+
+Will return something like:
+
+``` erlang
+["--name","John Smith","--path","John's Files","-u","jsmith"]
+```
+
 The other functions exported by the ``getopt`` module (``usage/2``, ``usage/3``
 and ``usage/4``) are used to show the command line syntax for the program.
 For example, given the above-mentioned option specifications, the call to
@@ -446,3 +463,22 @@ would return (depending on the value of your PATH variable) something like:
 ```
 
 Currently, *getopt* does not perform wildcard expansion of file paths.
+
+
+Escaping arguments
+==================
+
+Any character can be escaped by prepending the \ (backslash) character
+to it.
+
+e.g.
+
+``` erlang
+getopt:parse(OptSpecList, "--path /john\\'s\\ files dummy").
+```
+
+Will return:
+
+``` erlang
+{ok,{[{path,"/john's files"}],["dummy"]}}
+```
diff --git a/src/getopt.erl b/src/getopt.erl
@@ -11,8 +11,7 @@
 -module(getopt).
 -author('juanjo@comellas.org').
 
--export([parse/2, usage/2, usage/3, usage/4]).
--export([tokenize_cmdline/1]).
+-export([parse/2, usage/2, usage/3, usage/4, tokenize/1]).
 
 -export_type([arg_type/0,
 	      arg_value/0,
@@ -67,7 +66,7 @@ parse(OptSpecList, CmdLine) ->
     try
         Args = if
                    is_integer(hd(CmdLine)) ->
-                       tokenize_cmdline(CmdLine);
+                       tokenize(CmdLine);
                    true ->
                        CmdLine
                end,
@@ -612,12 +611,12 @@ add_option_help(_Opt, _Prefix, Acc) ->
 %%      The function also supports the expansion of environment variables in
 %%      both the Unix (${VAR}; $VAR) and Windows (%VAR%) formats. It does NOT
 %%      support wildcard expansion of paths.
--spec tokenize_cmdline(CmdLine :: string()) -> [string()].
-tokenize_cmdline(CmdLine) ->
-    tokenize_cmdline(CmdLine, [], []).
+-spec tokenize(CmdLine :: string()) -> [string()].
+tokenize(CmdLine) ->
+    tokenize(CmdLine, [], []).
 
--spec tokenize_cmdline(CmdLine :: string(), Acc :: [string()], ArgAcc :: string()) -> [string()].
-tokenize_cmdline([Sep | Tail], Acc, ArgAcc) when Sep =:= $\s; Sep =:= $\t; Sep =:= $\n ->
+-spec tokenize(CmdLine :: string(), Acc :: [string()], ArgAcc :: string()) -> [string()].
+tokenize([Sep | Tail], Acc, ArgAcc) when Sep =:= $\s; Sep =:= $\t; Sep =:= $\n ->
     NewAcc = case ArgAcc of
                  [_ | _] ->
                      %% Found separator: add to the list of arguments.
@@ -626,39 +625,39 @@ tokenize_cmdline([Sep | Tail], Acc, ArgAcc) when Sep =:= $\s; Sep =:= $\t; Sep =
                      %% Found separator with no accumulated argument; discard it.
                      Acc
              end,
-    tokenize_cmdline(Tail, NewAcc, []);
-tokenize_cmdline([QuotationMark | Tail], Acc, ArgAcc) when QuotationMark =:= $"; QuotationMark =:= $' ->
+    tokenize(Tail, NewAcc, []);
+tokenize([QuotationMark | Tail], Acc, ArgAcc) when QuotationMark =:= $"; QuotationMark =:= $' ->
     %% Quoted argument (might contain spaces, tabs, etc.)
     tokenize_quoted_arg(QuotationMark, Tail, Acc, ArgAcc);
-tokenize_cmdline([Char | _Tail] = CmdLine, Acc, ArgAcc) when Char =:= $$; Char =:= $% ->
+tokenize([Char | _Tail] = CmdLine, Acc, ArgAcc) when Char =:= $$; Char =:= $% ->
     %% Unix and Windows environment variable expansion: ${VAR}; $VAR; %VAR%
     {NewCmdLine, Var} = expand_env_var(CmdLine),
-    tokenize_cmdline(NewCmdLine, Acc, lists:reverse(Var, ArgAcc));
-tokenize_cmdline([$\\, Char | Tail], Acc, ArgAcc) ->
+    tokenize(NewCmdLine, Acc, lists:reverse(Var, ArgAcc));
+tokenize([$\\, Char | Tail], Acc, ArgAcc) ->
     %% Escaped char.
-    tokenize_cmdline(Tail, Acc, [Char | ArgAcc]);
-tokenize_cmdline([Char | Tail], Acc, ArgAcc) ->
-    tokenize_cmdline(Tail, Acc, [Char | ArgAcc]);
-tokenize_cmdline([], Acc, []) ->
+    tokenize(Tail, Acc, [Char | ArgAcc]);
+tokenize([Char | Tail], Acc, ArgAcc) ->
+    tokenize(Tail, Acc, [Char | ArgAcc]);
+tokenize([], Acc, []) ->
     lists:reverse(Acc);
-tokenize_cmdline([], Acc, ArgAcc) ->
+tokenize([], Acc, ArgAcc) ->
     lists:reverse([lists:reverse(ArgAcc) | Acc]).
 
 -spec tokenize_quoted_arg(QuotationMark :: char(), CmdLine :: string(), Acc :: [string()], ArgAcc :: string()) -> [string()].
 tokenize_quoted_arg(QuotationMark, [QuotationMark | Tail], Acc, ArgAcc) ->
     %% End of quoted argument
-    tokenize_cmdline(Tail, Acc, ArgAcc);
-tokenize_quoted_arg($" = QuotationMark, [Char | _Tail] = CmdLine, Acc, ArgAcc) when Char =:= $$; Char =:= $% ->
-    %% Unix and Windows environment variable expansion: ${VAR}; $VAR; %VAR%
-    {NewCmdLine, Var} = expand_env_var(CmdLine),
-    tokenize_quoted_arg(QuotationMark, NewCmdLine, Acc, lists:reverse(Var, ArgAcc));
+    tokenize(Tail, Acc, ArgAcc);
 tokenize_quoted_arg(QuotationMark, [$\\, Char | Tail], Acc, ArgAcc) ->
     %% Escaped char.
     tokenize_quoted_arg(QuotationMark, Tail, Acc, [Char | ArgAcc]);
+tokenize_quoted_arg($" = QuotationMark, [Char | _Tail] = CmdLine, Acc, ArgAcc) when Char =:= $$; Char =:= $% ->
+    %% Unix and Windows environment variable expansion (only for double-quoted arguments): ${VAR}; $VAR; %VAR%
+    {NewCmdLine, Var} = expand_env_var(CmdLine),
+    tokenize_quoted_arg(QuotationMark, NewCmdLine, Acc, lists:reverse(Var, ArgAcc));
 tokenize_quoted_arg(QuotationMark, [Char | Tail], Acc, ArgAcc) ->
     tokenize_quoted_arg(QuotationMark, Tail, Acc, [Char | ArgAcc]);
 tokenize_quoted_arg(_QuotationMark, CmdLine, Acc, ArgAcc) ->
-    tokenize_cmdline(CmdLine, Acc, ArgAcc).
+    tokenize(CmdLine, Acc, ArgAcc).
 
 
 -spec expand_env_var(CmdLine :: string()) -> string().
@@ -695,7 +694,7 @@ expand_env_var(Prefix, CmdLine, Acc) ->
 -spec get_env_var(Prefix :: string(), Suffix :: string(), Acc :: string()) -> string().
 get_env_var(Prefix, Suffix, [_ | _] = Acc) ->
     Name = lists:reverse(Acc),
-    %% Only expand valid variables.
+    %% Only expand valid/existing variables.
     case os:getenv(Name) of
         false -> Prefix ++ Name ++ Suffix;
         Value -> Value

diff --git a/test/getopt_test.erl b/test/getopt_test.erl
@@ -13,7 +13,7 @@
 
 -include_lib("eunit/include/eunit.hrl").
 
--import(getopt, [parse/2]).
+-import(getopt, [parse/2, tokenize/1]).
 
 -define(NAME(Opt), element(1, Opt)).
 -define(SHORT(Opt), element(2, Opt)).
@@ -274,3 +274,12 @@ parse_variable_expansion_test_() ->
       ?_assertEqual({ok, {[{path, "%PATH"}], ["%DUMMY_VAR_THAT_MUST_NOT_EXIST%"]}},
                     parse(OptSpecList, " --path %PATH %DUMMY_VAR_THAT_MUST_NOT_EXIST%  "))}
     ].
+
+
+tokenize_test_() ->
+    %% Path = os:getenv("PATH"),
+    [
+     {"Tokenize",
+      ?_assertEqual(["ABC","abc","1234","5678","DEFGHI","\"JKL \"", "$PATH"],
+                    tokenize("  ABC abc '1234' \"5678\" 'DEF'\"GHI\" '\"JKL \"'  \\$PATH"))}
+    ].