fix: make install colors not always shown

[grepsuzette]

In my terminals (konsole, kmscon, kmscon+tmux), colors won't show without -e in
echo -e "\033[0;32m blabla \033[0m".

The -e option enables interpretation of backslash escapes in the string, which
allows the color code \033[0;32m to work. With -e it should be more widely
supported across different platforms and shell environments.

$ help echo
echo: echo [-neE] [arg ...]
    Write arguments to the standard output.

    Display the ARGs, separated by a single space character and followed by a
    newline, on the standard output.

    Options:
      -n        do not append a newline
      -e        enable interpretation of the following backslash escapes
      -E        explicitly suppress interpretation of backslash escapes

    `echo' interprets the following backslash-escaped characters:
      \a        alert (bell)
      \b        backspace
      \c        suppress further output
      \e        escape character
      \E        escape character
      \f        form feed
      \n        new line
      \r        carriage return
      \t        horizontal tab
      \v        vertical tab
      \\        backslash
      \0nnn     the character whose ASCII code is NNN (octal).  NNN can be
                0 to 3 octal digits

An alternative is to directly input the escape character, or to use printf: printf "\033[0;32mHello\033[0m\n".

@leohhhh does it still work on your machine with echo -e? (what terminal are you using btw?)

[thehowl]

I don't get this problem, but doing a few tests I think it's because my shell is zsh and automatically converts it. The PR is sensible, merging.

[thehowl]

Actually, my shell prints the literal -e:

I looked this up, see UNIX stackexchange:

UNIX compliant implementations of echo are required to output -e<space>hello<newline>world<newline> there.

Those that don't are not compliant. Many aren't which means it's almost impossible to use echo portably, printf should be used instead. bash's echo, in some (most) builds of it, is only compliant when you enable both the posix and xpg_echo options. That might be the echo behaviour you were expecting.

I changed the implementation to use printf instead.