[GlitchMr]

It can also be Perl, as Perl supports `s///` syntax.

[laumars]

Doesn't need to be forward slashes (in either Perl or sed).

In fact that last example I might write as either of the two following ways:

    s,$,/,
    s{$}{/}    # this is supported in Perl but not sed

to avoid having to escape the replacing character.