New option: --list-frames

* NEWS: Update.
* src/cmdline.opt: New option --list-frames (-L)
* src/frametab.gperf: Use %global-table option.
(frametab_enumerate): New function.
* src/idest.h (frametab_enumerate): New proto.
* src/main.c: Implement --list-frames.

5 files changed, 91 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 71b10df..ed6ee32 100644
--- a/NEWS
+++ b/NEWS
@@ -34,6 +34,11 @@ The --filter=FRAME-LIST option can be used in conjunction with
 to the fields from FRAME-LIST.  The `--delete --filter=FRAME-LIST'
 is equivalent to `--delete=FRAME-LIST'.
 
+* New option --list-frames (-L)
+
+Lists the supported frames IDs, along with their qualifiers and
+descriptions.
+
 * The --convert option
 
 The argument to --convert option is either a single major version
diff --git a/src/cmdline.opt b/src/cmdline.opt
index 53cabf8..1400d2c 100644
--- a/src/cmdline.opt
+++ b/src/cmdline.opt
@@ -53,6 +53,8 @@ OPTIONS_BEGIN(gnu, "idest",
               [<idest - ID3 Edit and Scripting Tool>],
               [<FILE [FILE...]>])
 
+GROUP([<Operation mode>])
+
 OPTION(query,q,[FLIST],
        [<query mode>])
 BEGIN
@@ -101,6 +103,14 @@ BEGIN
         source_file = optarg;
 END
 
+OPTION(list-frames,L,,
+       [<list all supported frames>])
+BEGIN
+	SET_MODE(MODE_LIST);
+END
+
+GROUP([<Operation modifiers>])
+	
 OPTION(filter,F,FRAME-LIST,
        [<with --query, --copy and --delete: operate only on matching frames>])
 BEGIN
diff --git a/src/frametab.gperf b/src/frametab.gperf
index 83f3d9d..55ee1ed 100644
--- a/src/frametab.gperf
+++ b/src/frametab.gperf
@@ -460,6 +460,7 @@ wxxx_decode(struct ed_item *item, struct id3_frame const *frame)
 
 %}
 %define lookup-function-name idest_frame_lookup_len
+%global-table
 struct idest_frametab;
 %%
 COMM,	QUAL(COMM),	comm_cmp, comm_encode, comm_decode
@@ -520,11 +521,47 @@ WPAY,   0,  NULL,       NULL, url_encode, url_decode
 WPUB,   0,  NULL,       NULL, url_encode, url_decode
 WXXX,   QUAL(WXXX),     wxxx_cmp, wxxx_encode, wxxx_decode	 
 %%
+
+static int wordlist_count = sizeof(wordlist)/sizeof(wordlist[0]);	 
+
 const struct idest_frametab *
 idest_frame_lookup(const char *str)
 {
 	return idest_frame_lookup_len(str, strlen(str));
 }
+
+static int
+frametab_cmp(const void *a, const void *b)
+{
+	struct idest_frametab const *fta = a;
+	struct idest_frametab const *ftb = b;
+	return strcmp(fta->id, ftb->id);
+}
+
+int
+frametab_enumerate(int (*fun)(const struct idest_frametab *, void *),
+		   void *data, int sorted)
+{
+	struct idest_frametab *ft;
+	int i;
+
+	if (sorted) {
+		ft = xmalloc(sizeof(wordlist));
+		memcpy(ft, wordlist, sizeof(wordlist));
+		qsort(ft, wordlist_count, sizeof(ft[0]), frametab_cmp);
+	} else
+		ft = wordlist;
+	for (i = 0; i < wordlist_count; i++) {
+		int rc = fun(ft + i, data);
+		if (rc)
+			return rc;
+	}
+	if (sorted)
+		free(ft);
+	return 0;
+}
+
+
 /*
 Local variables:
 mode: c
diff --git a/src/idest.h b/src/idest.h
index 597e34b..2ae2b96 100644
--- a/src/idest.h
+++ b/src/idest.h
@@ -64,6 +64,7 @@ struct ed_item {
 #define MODE_MOD    1
 #define MODE_DELETE 2
 #define MODE_INFO   3
+#define MODE_LIST   4
 
 extern int mode;
 extern int latin1_option;
@@ -141,6 +142,8 @@ struct id3_frame *find_matching_frame(struct id3_tag *tag,
 				      const struct ed_item *item,
 				      idest_frame_cmp_t cmp);
 int frame_field_from_string(struct id3_frame *frame, int n, const char *value);
+int frametab_enumerate(int (*fun)(const struct idest_frametab *, void *),
+		       void *data, int sorted);
 
 
 /* main.c */
diff --git a/src/main.c b/src/main.c
index c213ec2..2d63b63 100644
--- a/src/main.c
+++ b/src/main.c
@@ -98,7 +98,36 @@ qv_free(size_t qc, char **qv)
 	free(qv);
 }
 
+#define DESCR_COLUMN 24
+static int
+describe_frame(const struct idest_frametab *ft, void *data)
+{
+	struct id3_frametype const *frametype;
+	int n;
+	
+	frametype = id3_frametype_lookup(ft->id, 4);
+	assert(frametype != NULL);
+	printf("%s", ft->id);
+	n = 0;
+	if (ft->qc) {
+		int i;
+		for (i = 0; i < ft->qc; i++)
+			n += printf(":%s", ft->qv[i]);
+	}
+	while (++n < DESCR_COLUMN)
+		putchar(' ');
+	
+	printf("%s\n", frametype->description);
+	return 0;
+}
 
+static void
+list_supported_frames(void)
+{
+	frametab_enumerate(describe_frame, NULL, 1);
+}
+
+
 void
 verify_mp3(FILE *fp, const char *name)
 {
@@ -174,6 +203,13 @@ main(int argc, char **argv)
 
 	guile_init(&argc, &argv);
 
+	if (mode == MODE_LIST) {
+		if (argc)
+			error(1, 0, "extra arguments");
+		list_supported_frames();
+		exit(0);
+	}
+	
 	if (argc == 0) 
 		error(1, 0, "no files");