• Go

p = strings.TrimSuffix(p, "/")

• Clojure

(clojure.string/replace p #"/$" "")

• Clojure

(defn remove-ending-slash
  [p]
  (if (clojure.string/ends-with? p "/")
    (subs p 0 (dec (count p)))
    s))

• C++

 if('/' == s.back())
  s.pop_back();

• C#

p = p.TrimEnd('/');

• D

p=p.chomp("/");

• D

auto p = "no_more_slashes///".stripRight!(a => a == '/');
writeln(p); // no_more_slashes

• Dart

if (p.endsWith("/")) p = p.substring(0, p.length - 1);

• Elixir

def main(string), do: String.replace_suffix(string, "/", "")

• Erlang

removeTrailingSlash([$/]) -> [];
removeTrailingSlash([]) -> [];
removeTrailingSlash([Ch | Rest]) ->
        [Ch] ++ removeTrailingSlash(Rest).

• Fortran

program x
character(len=:),allocatable :: string
integer :: ii
string='my string/'
ii=len(string)
string=trim(merge(string(:ii-1)//' ',string,string(ii:ii).eq.'/'))
write(*,*)string
end program x

• Haskell

slashscrape p = if last p == '/' then init p else p

• JS

const slashscrape = p => (
  p.slice (-1) === '/' ?
    p.slice (0, -1) :
    p
)

• Java

int n = p.length() - 1;
while (n != 0 && p.charAt(n) == '/')
    p = p.substring(0, n--);

• Java

p = p.replaceAll("(?<!^)/+$", "");

• Java

if (p.endsWith("/")) {
    p = p.substring(0, p.length() - 1);
}

• Java

p = p.replaceAll("/$", "");

• Lisp

(defun remove-trailing-slash (string)
  "Return a copy of STRING removing one trailing slash character, if any."
  (let ((position (position #\/ string :from-end t)))
    (if (eql position (1- (length string)))
        (subseq string 0 position)
        (copy-seq string))))

(setf p (remove-trailing-slash p))

• Lisp

(setf p (string-right-trim "/" p))

• Lua

p = string.gsub(p,"/$","")

• PHP

$p = rtrim($p, '/');

• Pascal

var
  Len: Integer;
begin
  Len := Length(p);
  if (Len > 0) and (p[Len] = '/') then Delete(P, Len, 1);
end;

• Pascal

begin
  AllowDirectorySeparators := AllowDirectorySeparators + ['/'];
  p := ExcludeTrailingPathDelimiter(p);
end;

• Perl

$p =~ s{/$}{};

• Perl

{ local $/='/'; chomp $p }

• Python

p = p.rstrip("/")

• Ruby

p.chomp!("/")

• Ruby

p = p.chomp("/")

• Rust

if p.ends_with('/') { p.pop(); }

• Scala

p.stripSuffix("/")