Implement the --info option.

* NEWS: Update.
* configure.ac: Version 1.2.90
* doc/idest.texi: Document the --info option.
* libid3tag/file.c (id3_file_struct_ntags)
(id3_file_struct_iterate): New functions.
* libid3tag/file.h (id3_file_struct_ntags)
(id3_file_struct_iterate): New protos.
(id3_file_struct_iterator_t): New data type.
* src/cmdline.opt: New option --info.
* src/idest.h (info_id3): New proto.
(del_id3v2): Remove.
* src/idop.c (info_id3): New function.
* src/main.c (id3_mode): Add info_id3.

1 files changed, 31 insertions, 2 deletions

diff --git a/doc/idest.texi b/doc/idest.texi
index 9ad7fd0..e2b2a8b 100644
--- a/doc/idest.texi
+++ b/doc/idest.texi
@@ -78,6 +78,7 @@ documents IdEst @value{VERSION}.
 * Modify::               Modifying Existing Tags
 * Delete::               Deleting Tags
 * ID Versioning::        Storing Tags in Different ID3 Versions
+* Structure::            Examining File Structure
 * Scripting::            Scripting
 * Backups::              Keeping Backup Copies
 * Invocation::           Invocation Summary
@@ -344,8 +345,32 @@ changes the @samp{artist} field and duplicates the ID3 data ID3v1
 format.  Thus, the resulting file will have two copies of the same ID3
 data in two different formats.
 
-When used alone, this option causes duplication of existing ID3v2 data
-in ID3v1 format.
+@node Structure
+@chapter Examining File Structure
+
+  The @option{--info} (@option{-i}) option instructs @command{idest}
+to show the structure of input files.  The output is formatted as
+a sequence of keyword / value pairs, as shown in the example below:
+
+@example
+$ idest --info jt_lluny.mp3
+file: jt_lluny.mp3
+ntags: 2
+version: 4.0
+offset: 0
+length: 2131
+version: 1.1
+offset: 2725554
+length: 128
+@end example
+
+The first two lines show the name of the input file and the number of
+ID3 tags in it.  Following are tag descriptions formatted as three
+values for each tag.  The @samp{version} line shows the tag version
+(major and minor numbers, separated by a dot).  The major number greater
+than 1 means it is a ID3v2 tag.  The @samp{offset} line shows the
+offset of this tag in the file, and the @samp{length} line contains
+the size of this tag in bytes.
 
 @node Scripting
 @chapter Scripting
@@ -603,6 +628,10 @@ Guile function to call.  @xref{Scripting}.
 @itemx --help
 Print a short help list.
 
+@item -i
+@itemx --info
+Show tag structure information.  @xref{Structure}.
+
 @item --latin1
 Force latin1 output, when used in query mode (@pxref{View,latin1}).
 Store strings in ISO-8859-1 encoding, when used with @option{--set}