file_utils: Add a new get_file_size function

The get_file_size function allows to conveniently get the size of the file.

Signed-off-by: Adrian Warecki <adrian.warecki@intel.com>

src/file_utils.c

@@ -36,3 +36,38 @@ int create_file_name(char *new_name, const size_t name_size, const char *templat
 
 	return 0;
 }
+
+/**
+ * Get file size
+ * @param [in] f file handle
+ * @param [in] filename File name used to display the error message
+ * @param [out] size output for file size
+ * @param error code, 0 when success
+ */
+int get_file_size(FILE *f, const char* filename, size_t *size)
+{
+	int ret;
+
+	assert(size);
+
+	/* get file size */
+	ret = fseek(f, 0, SEEK_END);
+	if (ret < 0) {
+		fprintf(stderr, "error: unable to seek eof %s %d\n", filename, errno);
+		return -errno;
+	}
+
+	*size = ftell(f);
+	if (*size < 0) {
+		fprintf(stderr, "error: unable to get file size for %s %d\n", filename, errno);
+		return -errno;
+	}
+
+	ret = fseek(f, 0, SEEK_SET);
+	if (ret < 0) {
+		fprintf(stderr, "error: unable to seek set %s %d\n", filename, errno);
+		return -errno;
+	}
+
+	return 0;
+}

src/include/rimage/file_utils.h

@@ -19,4 +19,13 @@
 int create_file_name(char *new_name, const size_t name_size, const char *template_name,
 		     const char *new_ext);
 
+/**
+ * Get file size
+ * @param [in] f file handle
+ * @param [in] filename File name used to display the error message
+ * @param [out] size output for file size
+ * @param error code, 0 when success
+ */
+int get_file_size(FILE *f, const char *filename, size_t *size);
+
 #endif /* __FILE_UTILS_H__ */