edid-decode: add --extract and --check options

Use --extract to extract the contents of the first EDID block
as hex values. The was the default in old versions, use this
option to see this data again. I don't see the use of this
hex dump, so I turned it off by default.

If you want to check the EDID if it conforms to the standards,
then use the --check option.

So now the default behavior of edid-decode when run without these
options is to just parse the EDID and show it in human-readable text,
which is what you want.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

2 files changed, 28 insertions, 6 deletions

diff --git a/edid-decode.1 b/edid-decode.1
index 652ad56..7c9789a 100644
--- a/edid-decode.1
+++ b/edid-decode.1
@@ -39,6 +39,14 @@ hex: hex numbers in ascii text (default for stdout)
 raw: binary data (default unless writing to stdout)
 .br
 carray: c-program struct
+.TP
+\fB\-c\fR, \fB\-\-check\fR
+Check if the EDID conforms to the standards.
+.TP
+\fB\-e\fR, \fB\-\-extract\fR
+Extract the contents of the first block in hex values.
+This was always done in old edid-decode versions. To get
+the same behavior add this option.
 
 .PP
 .SH NOTES
diff --git a/edid-decode.c b/edid-decode.c
index c643454..6b02514 100644
--- a/edid-decode.c
+++ b/edid-decode.c
@@ -111,8 +111,14 @@ enum output_format {
 	OUT_FMT_CARRAY
 };
 
-/* Options */
+/*
+ * Options
+ * Please keep in alphabetical order of the short option.
+ * That makes it easier to see which options are still free.
+ */
 enum Option {
+	OptCheck = 'c',
+	OptExtract = 'e',
 	OptHelp = 'h',
 	OptOutputFormat = 'o',
 	OptLast = 256
@@ -121,10 +127,10 @@ enum Option {
 static char options[OptLast];
 
 static struct option long_options[] = {
-	/* Please keep in alphabetical order of the short option.
-	   That makes it easier to see which options are still free. */
 	{ "help", no_argument, 0, OptHelp },
 	{ "output-format", required_argument, 0, OptOutputFormat },
+	{ "extract", no_argument, 0, OptExtract },
+	{ "check", no_argument, 0, OptCheck },
 	{ 0, 0, 0, 0 }
 };
 
@@ -136,13 +142,15 @@ static void usage(void)
 	       "  [out]                 Output the read EDID to this file. Write to standard output\n"
 	       "                        if the output filename is '-'.\n"
 	       "\nOptions:\n"
-	       "  -h, --help            display this help message\n"
 	       "  -o, --output-format=<fmt>\n"
 	       "                        if [out] is specified, then write the EDID in this format\n"
 	       "                        <fmt> is one of:\n"
 	       "                        hex:    hex numbers in ascii text (default for stdout)\n"
 	       "                        raw:    binary data (default unless writing to stdout)\n"
-	       "                        carray: c-program struct\n");
+	       "                        carray: c-program struct\n"
+	       "  -c, --check           check if the EDID conforms to the standards\n"
+	       "  -e, --extract         extract the contents of the first block in hex values\n"
+	       "  -h, --help            display this help message\n");
 }
 
 struct value {
@@ -2902,7 +2910,8 @@ static int edid_from_file(const char *from_file, const char *to_file,
 		fclose(out);
 	}
 
-	dump_breakdown(edid);
+	if (options[OptExtract])
+		dump_breakdown(edid);
 
 	if (!edid || memcmp(edid, "\x00\xFF\xFF\xFF\xFF\xFF\xFF\x00", 8)) {
 		fprintf(stderr, "No header found\n");
@@ -3156,6 +3165,11 @@ static int edid_from_file(const char *from_file, const char *to_file,
 		nonconformant_extension += parse_extension(x);
 	}
 
+	if (!options[OptCheck]) {
+		free(edid);
+		return 0;
+	}
+
 	if (claims_one_point_three) {
 		if (nonconformant_digital_display ||
 		    nonconformant_hf_vsdb_position ||