output: Added preferred file extension field

This fixes parts of bug #541.

bindings/cxx/classes.cpp

@@ -1534,6 +1534,15 @@ string OutputFormat::description()
 	return valid_string(sr_output_description_get(_structure));
 }
 
+vector<string> OutputFormat::extensions()
+{
+	vector<string> exts;
+	for (const char *const *e = sr_output_extensions_get(_structure);
+		e && *e; e++)
+		exts.push_back(*e);
+	return exts;
+}
+
 map<string, shared_ptr<Option>> OutputFormat::options()
 {
 	const struct sr_option **options = sr_output_options_get(_structure);

bindings/cxx/include/libsigrokcxx/libsigrokcxx.hpp

@@ -948,6 +948,9 @@ public:
 	string name();
 	/** Description of this output 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 output format. */
 	map<string, shared_ptr<Option> > options();
 	/** Create an output using this format.

include/libsigrok/proto.h

@@ -170,6 +170,8 @@ SR_API const struct sr_output_module **sr_output_list(void);
 SR_API const char *sr_output_id_get(const struct sr_output_module *o);
 SR_API const char *sr_output_name_get(const struct sr_output_module *o);
 SR_API const char *sr_output_description_get(const struct sr_output_module *o);
+SR_API const char *const *sr_output_extensions_get(
+		const struct sr_output_module *o);
 SR_API const struct sr_output_module *sr_output_find(char *id);
 SR_API const struct sr_option **sr_output_options_get(const struct sr_output_module *o);
 SR_API void sr_output_options_free(const struct sr_option **opts);

src/libsigrok-internal.h

@@ -371,6 +371,13 @@ struct sr_output_module {
 	 */
 	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;
+
 	/**
 	 * Returns a NULL-terminated list of options this module can take.
 	 * Can be NULL, if the module has no options.

src/output/analog.c

@@ -344,6 +344,7 @@ SR_PRIV struct sr_output_module output_analog = {
 	.id = "analog",
 	.name = "Analog",
 	.desc = "Analog data and types",
+	.exts = NULL,
 	.options = get_options,
 	.init = init,
 	.receive = receive,

src/output/ascii.c

@@ -252,6 +252,7 @@ SR_PRIV struct sr_output_module output_ascii = {
 	.id = "ascii",
 	.name = "ASCII",
 	.desc = "ASCII art",
+	.exts = (const char*[]){"txt", NULL},
 	.options = get_options,
 	.init = init,
 	.receive = receive,

src/output/binary.c

@@ -46,6 +46,7 @@ SR_PRIV struct sr_output_module output_binary = {
 	.id = "binary",
 	.name = "Binary",
 	.desc = "Raw binary",
+	.exts = NULL,
 	.options = NULL,
 	.receive = receive,
 };

src/output/bits.c

@@ -238,6 +238,7 @@ SR_PRIV struct sr_output_module output_bits = {
 	.id = "bits",
 	.name = "Bits",
 	.desc = "0/1 digits",
+	.exts = (const char*[]){"txt", NULL},
 	.options = get_options,
 	.init = init,
 	.receive = receive,

src/output/chronovu_la8.c

@@ -187,6 +187,7 @@ SR_PRIV struct sr_output_module output_chronovu_la8 = {
 	.id = "chronovu-la8",
 	.name = "ChronoVu LA8",
 	.desc = "ChronoVu LA8 native file format",
+	.exts = (const char*[]){"kdt", NULL},
 	.options = NULL,
 	.init = init,
 	.receive = receive,

src/output/csv.c

@@ -217,6 +217,7 @@ SR_PRIV struct sr_output_module output_csv = {
 	.id = "csv",
 	.name = "CSV",
 	.desc = "Comma-separated values",
+	.exts = (const char*[]){"csv", NULL},
 	.options = NULL,
 	.init = init,
 	.receive = receive,

src/output/gnuplot.c

@@ -221,6 +221,7 @@ SR_PRIV struct sr_output_module output_gnuplot = {
 	.id = "gnuplot",
 	.name = "Gnuplot",
 	.desc = "Gnuplot file format",
+	.exts = (const char*[]){"pl", NULL},
 	.options = NULL,
 	.init = init,
 	.receive = receive,

src/output/hex.c

@@ -252,6 +252,7 @@ SR_PRIV struct sr_output_module output_hex = {
 	.id = "hex",
 	.name = "Hexadecimal",
 	.desc = "Hexadecimal digits",
+	.exts = (const char*[]){"txt", NULL},
 	.options = get_options,
 	.init = init,
 	.receive = receive,

src/output/ols.c

@@ -150,6 +150,7 @@ SR_PRIV struct sr_output_module output_ols = {
 	.id = "ols",
 	.name = "OLS",
 	.desc = "OpenBench Logic Sniffer",
+	.exts = (const char*[]){"ols", NULL},
 	.options = NULL,
 	.init = init,
 	.receive = receive,

src/output/output.c

@@ -135,6 +135,25 @@ SR_API const char *sr_output_description_get(const struct sr_output_module *o)
 	return o->desc;
 }
 
+/**
+ * Returns the specified output 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_output_extensions_get(
+		const struct sr_output_module *o)
+{
+	if (!o) {
+		sr_err("Invalid output module NULL!");
+		return NULL;
+	}
+
+	return o->exts;
+}
+
 /**
  * Return the output module with the specified ID, or NULL if no module
  * with that id is found.

src/output/srzip.c

@@ -312,6 +312,7 @@ SR_PRIV struct sr_output_module output_srzip = {
 	.id = "srzip",
 	.name = "srzip",
 	.desc = "srzip session file",
+	.exts = (const char*[]){"sr", NULL},
 	.options = get_options,
 	.init = init,
 	.receive = receive,

src/output/vcd.c

@@ -263,6 +263,7 @@ struct sr_output_module output_vcd = {
 	.id = "vcd",
 	.name = "VCD",
 	.desc = "Value Change Dump",
+	.exts = (const char*[]){"vcd", NULL},
 	.options = NULL,
 	.init = init,
 	.receive = receive,

src/output/wav.c

@@ -351,6 +351,7 @@ SR_PRIV struct sr_output_module output_wav = {
 	.id = "wav",
 	.name = "WAV",
 	.desc = "WAVE file format",
+	.exts = (const char*[]){"wav", NULL},
 	.options = get_options,
 	.init = init,
 	.receive = receive,