main: add --version=NONE option for printing the version number in simplified style

Close #2361.

Signed-off-by: Masatake YAMATO <[email protected]>

Author: masatake

docs/man/ctags.1.rst

@@ -1327,12 +1327,14 @@ Miscellaneous Options
 ``-V``
 	Equivalent to ``--verbose``.
 
-``--version[=<language>]``
+``--version[=<language>|NONE]``
 	Prints a version identifier for ctags to standard
 	output, and then exits. This is guaranteed to always contain the string
 	"Universal Ctags". See also the description for ``TAG_PROGRAM_VERSION``
 	and ``TAG_OUTPUT_VERSION`` in :ref:`ctags-client-tools(7) <ctags-client-tools(7)>`.
 
+	If ``NONE`` is given, prints the version identifier in a simplified way.
+
 	If *<language>* is given, print the version identifier for the parser
 	for *<language>*. See also the description for ``TAG_PARSER_VERSION`` in
 	:ref:`ctags-client-tools(7) <ctags-client-tools(7)>`.

main/options.c

@@ -2687,6 +2687,14 @@ static void processVersionOption (
 {
 	if (parameter == NULL || *parameter == '\0')
 		printProgramIdentification ();
+	else if (strcmp (parameter, RSV_NONE) == 0)
+	{
+		printf("ctags: %s\n", PROGRAM_VERSION);
+		if (! ((ctags_repoinfo == NULL)
+			   || (strcmp (ctags_repoinfo, PROGRAM_VERSION) == 0)))
+			printf("repoinfo: %s\n", ctags_repoinfo);
+		printf("output: %d.%d\n", OUTPUT_VERSION_CURRENT, OUTPUT_VERSION_AGE);
+	}
 	else
 	{
 		langType language = getNamedLanguage (parameter, 0);

man/ctags.1.rst.in

@@ -1327,12 +1327,14 @@ Miscellaneous Options
 ``-V``
 	Equivalent to ``--verbose``.
 
-``--version[=<language>]``
+``--version[=<language>|NONE]``
 	Prints a version identifier for @CTAGS_NAME_EXECUTABLE@ to standard
 	output, and then exits. This is guaranteed to always contain the string
 	"Universal Ctags". See also the description for ``TAG_PROGRAM_VERSION``
 	and ``TAG_OUTPUT_VERSION`` in ctags-client-tools(7).
 
+	If ``NONE`` is given, prints the version identifier in a simplified way.
+
 	If *<language>* is given, print the version identifier for the parser
 	for *<language>*. See also the description for ``TAG_PARSER_VERSION`` in
 	ctags-client-tools(7).