Enable output of extrated file to stdout.

fdtextract.c

@@ -96,11 +96,6 @@ static int extract_image(char *buf, char *name, char *out)
 	unsigned int data_size, data_offset;
 	const fdt32_t *val;
 
-	if (!out) {
-		printf("Error: please specify output file name.\n");
-		return -1;
-	}
-
 	snprintf(path, MAX_PATH_LEN, "/images/%s", name);
 	noffset = fdt_path_offset(buf, path);
 	if (noffset < 0) {
@@ -108,8 +103,6 @@ static int extract_image(char *buf, char *name, char *out)
 		return -1;
 	}
 
-	printf("Extracting %s to %s.\n", name, out);
-
 	/* Get offset of image. Try both relative and absolute offset. */
 	val = fdt_getprop(buf, noffset, "data-offset", NULL);
 	if(val) {
@@ -135,11 +128,18 @@ static int extract_image(char *buf, char *name, char *out)
 
 	data_size = fdt32_to_cpu(*val);
 
-	fd = open(out, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-	if (fd < 0) {
-		printf("Error opening output file %s.\n", out);
-		return errno;
+	/* If output file is provided, write to that file. If not, write
+	   to stdout. */
+	if (out) {
+		fd = open(out, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+		if (fd < 0) {
+			printf("Error opening output file %s.\n", out);
+			return errno;
+		}
+	} else {
+		fd = STDOUT_FILENO;
 	}
+
 	count = write(fd, buf + data_offset, data_size);
 	if (count < data_size) {
 		printf("Error writing output file %s.\n", out);