allow some more stdin/stout I/O
* allow reading from stdin for dwebp / vwebp
* allow writing to stdout for gif2webp
by introducing a new function ExUtilReadFromStdin()
Example use: cat in.webp | dwebp -o - -- - > out.png
Note that the '-- -' option must appear *last*
(as per general fashion for '--' option parsing)
Change-Id: I8df0f3a246cc325925d6b6f668ba060f7dd81d68
diff --git a/examples/example_util.h b/examples/example_util.h
index b478025..b191bd2 100644
--- a/examples/example_util.h
+++ b/examples/example_util.h
@@ -22,10 +22,16 @@
// Allocates storage for entire file 'file_name' and returns contents and size
// in 'data' and 'data_size'. Returns 1 on success, 0 otherwise. '*data' should
// be deleted using free().
+// If 'file_name' is NULL or equal to "-", input is read from stdin by calling
+// the function ExUtilReadFromStdin().
int ExUtilReadFile(const char* const file_name,
const uint8_t** data, size_t* data_size);
+// Same as ExUtilReadFile(), but reads until EOF from stdin instead.
+int ExUtilReadFromStdin(const uint8_t** data, size_t* data_size);
+
// Write a data segment into a file named 'file_name'. Returns true if ok.
+// If 'file_name' is NULL or equal to "-", output is written to stdout.
int ExUtilWriteFile(const char* const file_name,
const uint8_t* data, size_t data_size);