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Programming-Idioms

  • JS
  • Lisp

Idiom #150 Remove trailing slash

Remove the last character from the string p, if this character is a forward slash /

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

This removes all trailing slashes, not only the last one.
(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))

We only remove a single slash. To remove all ending slashes one can use STRING-RIGHT-TRIM.

POSITION returns the index of the first matching element. The FROM-END keyword causes it to work in reverse, returning the index of the last matching element.

Though it isn't strictly necessary to make a new copy of strings which don't end in a slash, SUBSEQ already does copy its argument and it seems best to be consistent.
const slashscrape = p => (
  p.slice (-1) === '/' ?
    p.slice (0, -1) :
    p
)
(clojure.string/replace p #"/$" "")

Ensure the regex has a $ at the end!
New implementation...
< > ⌨
programming-idioms.org 
(setf p (string-right-trim "/" p))
(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))

const slashscrape = p => (
  p.slice (-1) === '/' ?
    p.slice (0, -1) :
    p
)
(clojure.string/replace p #"/$" "")
(defn remove-ending-slash
  [p]
  (if (clojure.string/ends-with? p "/")
    (subs p 0 (dec (count p)))
    s))
 if('/' == s.back())
  s.pop_back();
p = p.TrimEnd('/');
auto p = "no_more_slashes///".stripRight!(a => a == '/');
writeln(p); // no_more_slashes
p=p.chomp("/");
if (p.endsWith("/")) p = p.substring(0, p.length - 1);
def main(string), do: String.replace_suffix(string, "/", "")
removeTrailingSlash([$/]) -> [];
removeTrailingSlash([]) -> [];
removeTrailingSlash([Ch | Rest]) ->
        [Ch] ++ removeTrailingSlash(Rest).
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

p = strings.TrimSuffix(p, "/")
slashscrape p = if last p == '/' then init p else p
p = p.replaceAll("(?<!^)/+$", "");
int n = p.length() - 1;
while (n != 0 && p.charAt(n) == '/')
    p = p.substring(0, n--);
if (p.endsWith("/")) {
    p = p.substring(0, p.length() - 1);
}
p = p.replaceAll("/$", "");
p = string.gsub(p,"/$","")
$p = rtrim($p, '/');
var
  Len: Integer;
begin
  Len := Length(p);
  if (Len > 0) and (p[Len] = '/') then Delete(P, Len, 1);
end;
begin
  AllowDirectorySeparators := AllowDirectorySeparators + ['/'];
  p := ExcludeTrailingPathDelimiter(p);
end;
$p =~ s{/$}{};
{ local $/='/'; chomp $p }
p = p.rstrip("/")
p.chomp!("/")
p = p.chomp("/")
if p.ends_with('/') { p.pop(); }
p.stripSuffix("/")