use `cat -v installer.sh`
-v Displays non-printing characters so they are visible. Control
characters print as `^X' for control-X, with the exception of the
tab and EOL characters, which are displayed normally. The tab
character, control-I, can be made visible via the -t option. The
DEL character (octal 0177) prints as `^?'. Non-ASCII characters
(with the high bit set) are printed as `M-' (for meta) followed
by the character for the low 7 bits.