input: Added preferred file extension field

This fixes parts of bug #541.

bindings/cxx/classes.cpp

@@ -1385,6 +1385,15 @@ string InputFormat::description()
 	return valid_string(sr_input_description_get(_structure));
 }
 
+vector<string> InputFormat::extensions()
+{
+	vector<string> exts;
+	for (const char *const *e = sr_input_extensions_get(_structure);
+		e && *e; e++)
+		exts.push_back(*e);
+	return exts;
+}
+
 map<string, shared_ptr<Option>> InputFormat::options()
 {
 	const struct sr_option **options = sr_input_options_get(_structure);

bindings/cxx/include/libsigrokcxx/libsigrokcxx.hpp

@@ -865,6 +865,9 @@ public:
 	string name();
 	/** Description of this input format. */
 	string description();
+	/** A list of preferred file name extensions for this file format.
+         * @note This list is a recommendation only. */
+	vector<string> extensions();
 	/** Options supported by this input format. */
 	map<string, shared_ptr<Option> > options();
 	/** Create an input using this input format.

include/libsigrok/proto.h

@@ -150,6 +150,8 @@ SR_API const struct sr_input_module **sr_input_list(void);
 SR_API const char *sr_input_id_get(const struct sr_input_module *in);
 SR_API const char *sr_input_name_get(const struct sr_input_module *in);
 SR_API const char *sr_input_description_get(const struct sr_input_module *in);
+SR_API const char *const *sr_input_extensions_get(
+		const struct sr_input_module *o);
 SR_API const struct sr_input_module *sr_input_find(char *id);
 SR_API const struct sr_option **sr_input_options_get(const struct sr_input_module *in);
 SR_API void sr_input_options_free(const struct sr_option **options);

src/input/binary.c

@@ -165,6 +165,7 @@ SR_PRIV struct sr_input_module input_binary = {
 	.id = "binary",
 	.name = "Binary",
 	.desc = "Raw binary",
+	.exts = NULL,
 	.options = get_options,
 	.init = init,
 	.receive = receive,

src/input/chronovu_la8.c

@@ -177,6 +177,7 @@ SR_PRIV struct sr_input_module input_chronovu_la8 = {
 	.id = "chronovu-la8",
 	.name = "Chronovu-LA8",
 	.desc = "ChronoVu LA8",
+	.exts = (const char*[]){"kdt", NULL},
 	.metadata = { SR_INPUT_META_FILESIZE | SR_INPUT_META_REQUIRED },
 	.options = get_options,
 	.format_match = format_match,

src/input/csv.c

@@ -819,6 +819,7 @@ SR_PRIV struct sr_input_module input_csv = {
 	.id = "csv",
 	.name = "CSV",
 	.desc = "Comma-separated values",
+	.exts = (const char*[]){"csv", NULL},
 	.metadata = { SR_INPUT_META_MIMETYPE },
 	.options = get_options,
 	.format_match = format_match,

src/input/input.c

@@ -129,6 +129,25 @@ SR_API const char *sr_input_description_get(const struct sr_input_module *o)
 	return o->desc;
 }
 
+/**
+ * Returns the specified input module's file extensions typical for the file
+ * format, as a NULL terminated array, or returns a NULL pointer if there is
+ * no preferred extension.
+ * @note these are a suggestions only.
+ *
+ * @since 0.4.0
+ */
+SR_API const char *const *sr_input_extensions_get(
+		const struct sr_input_module *o)
+{
+	if (!o) {
+		sr_err("Invalid input module NULL!");
+		return NULL;
+	}
+
+	return o->exts;
+}
+
 /**
  * Return the input module with the specified ID, or NULL if no module
  * with that id is found.

src/input/vcd.c

@@ -569,6 +569,7 @@ SR_PRIV struct sr_input_module input_vcd = {
 	.id = "vcd",
 	.name = "VCD",
 	.desc = "Value Change Dump",
+	.exts = (const char*[]){"vcd", NULL},
 	.metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 	.options = get_options,
 	.format_match = format_match,

src/input/wav.c

@@ -365,6 +365,7 @@ SR_PRIV struct sr_input_module input_wav = {
 	.id = "wav",
 	.name = "WAV",
 	.desc = "WAV file",
+	.exts = (const char*[]){"wav", NULL},
 	.metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
 	.format_match = format_match,
 	.init = init,

src/libsigrok-internal.h

@@ -238,6 +238,13 @@ struct sr_input_module {
 	 */
 	const char *desc;
 
+	/**
+	 * A NULL terminated array of strings containing a list of file name
+	 * extensions typical for the input file format, or NULL if there is
+	 * no typical extension for this file format.
+	 */
+	const char *const *exts;
+
 	/**
 	 * Zero-terminated list of metadata items the module needs to be able
 	 * to identify an input stream. Can be all-zero, if the module cannot