s4_right( string, n )

Expands to n characters from the right side of the string:

⇐ {s4_right([String], [3])}

⇒ {ing}

Leading and trailing whitespace is trimmed from n:

⇐ {s4_right([String], [
⇐     3
⇐ ])}

⇒ {ing}

n can be signed, both plus and minus signs are allowed:

⇐ {s4_right([String], [+3])}

⇒ {ing}

If n is zero or negative, result is empty:

⇐ {s4_right([String], [-3])}

⇒ {}

If n is greather than string length, entire string is returned:

⇐ {s4_right([String], [10])}

⇒ {String}

Result is quoted:

⇐ {s4_right([m4_toupper([String])], [20])}

⇒ {m4_toupper([String])}

(Note: m4_toupper macro is not expanded.)

Beware: M4 v1.4.18 is not Unicode-aware, it considers every single byte as a character. So, using s4_right with non-ASCII strings can produce misleading result and/or invalid Unicode.

⇐ {s4_right([Фыва], [4])}

⇒ {ва}

(Note: 4 characters requested but 2 characters actually returned. Requesting odd number of characters will likely cause invalid Unicode.)