xdiff_file_diff() makes unified diff of files file1 and file2 and stores result in file dest. context indicated how many lines of context you want to include in diff result. Set minimal to TRUE if you want to minimalize size of diff (can take a long time).
성공일 경우 TRUE를, 실패일 경우 FALSE를 반환합니다.
See also xdiff_string_diff().