2016 Update

Task/Find-common-directory-path/00DESCRIPTION

@@ -8,7 +8,8 @@ Test your routine using the forward slash '/' character as the directory separat
 Note: The resultant path should be the valid directory <code>'/home/user1/tmp'</code> and not the longest common string <code>'/home/user1/tmp/cove'</code>.<br>
 If your language has a routine that performs this function (even if it does not have a changeable separator character), then mention it as part of the task.
 
-'''''See Also:'''''
+
+;Related tasks
 * [[Longest common prefix]]
 
-<br>
+<br><br>

Task/Find-common-directory-path/Perl-6/find-common-directory-path-2.pl6

@@ -3,7 +3,7 @@ my @dirs := </home/user1/tmp/coverage/test
              /home/user1/tmp/covert/operator
              /home/user1/tmp/coven/members>;
 
-my @comps := @dirs.map: { [ .comb(/ $sep [ <!before $sep> . ]* /) ] };
+my @comps = @dirs.map: { [ .comb(/ $sep [ <!before $sep> . ]* /) ] };
 
 say "The longest common path is ",
     gather for 0..* -> $column {

Task/Find-common-directory-path/Python/find-common-directory-path-3.py

@@ -1,16 +1,3 @@
->>> from itertools import takewhile
->>> def allnamesequal(name):
-	return all(n==name[0] for n in name[1:])
-
->>> def commonprefix(paths, sep='/'):
-	bydirectorylevels = zip(*[p.split(sep) for p in paths])
-	return sep.join(x[0] for x in takewhile(allnamesequal, bydirectorylevels))
-
->>> commonprefix(['/home/user1/tmp/coverage/test',
-                  '/home/user1/tmp/covert/operator', '/home/user1/tmp/coven/members'])
+>>> paths = ['/home/user1/tmp/coverage/test', '/home/user1/tmp/covert/operator', '/home/user1/tmp/coven/members']
+>>> os.path.dirname(os.path.commonprefix(paths))
 '/home/user1/tmp'
->>> # And also
->>> commonprefix(['/home/user1/tmp', '/home/user1/tmp/coverage/test',
-                  '/home/user1/tmp/covert/operator', '/home/user1/tmp/coven/members'])
-'/home/user1/tmp'
->>>

Task/Find-common-directory-path/Python/find-common-directory-path-4.py

@@ -0,0 +1,16 @@
+>>> from itertools import takewhile
+>>> def allnamesequal(name):
+	return all(n==name[0] for n in name[1:])
+
+>>> def commonprefix(paths, sep='/'):
+	bydirectorylevels = zip(*[p.split(sep) for p in paths])
+	return sep.join(x[0] for x in takewhile(allnamesequal, bydirectorylevels))
+
+>>> commonprefix(['/home/user1/tmp/coverage/test',
+                  '/home/user1/tmp/covert/operator', '/home/user1/tmp/coven/members'])
+'/home/user1/tmp'
+>>> # And also
+>>> commonprefix(['/home/user1/tmp', '/home/user1/tmp/coverage/test',
+                  '/home/user1/tmp/covert/operator', '/home/user1/tmp/coven/members'])
+'/home/user1/tmp'
+>>>

Task/Find-common-directory-path/REXX/find-common-directory-path.rexx

@@ -1,15 +1,16 @@
-/*REXX program finds  common directory path  for a list of files.       */
-@.=                                    /*define all file lists to null. */
-@.1 = '/home/user1/tmp/coverage/test'
-@.2 = '/home/user1/tmp/covert/operator'
-@.3 = '/home/user1/tmp/coven/members'
-L=length(@.1)
-                do j=2  while @.j\=='' /*start with the second string.  */
-                _ = compare(@.j,@.1);  if _==0  then iterate    /*equal.*/
-                L = min(L,_)           /*find the minimum equal strings.*/
+/*REXX program  finds  the  common directory path  for a list of files.                 */
+         @.  =                                   /*the default for all file lists (null)*/
+         @.1 = '/home/user1/tmp/coverage/test'
+         @.2 = '/home/user1/tmp/covert/operator'
+         @.3 = '/home/user1/tmp/coven/members'
+L=length(@.1)                                    /*use the length of the first string.  */
+                do j=2  while  @.j\==''          /*start search with the second string. */
+                _=compare(@.j, @.1)              /*use REXX  compare  BIF for comparison*/
+                if _==0  then iterate            /*Strings are equal? Then they're equal*/
+                L=min(L, _)                      /*find the minimum length equal strings*/
                 end   /*j*/
 
-common = left(@.1,lastpos('/',@.1,L))  /*find the shortest  DIR  string.*/
-if right(common,1)=='/'  then common=left(common, max(0,length(common)-1))
-say 'common directory path: ' common   /*[↑] handle trailing / delimiter*/
-                                       /*stick a fork in it, we're done.*/
+common=left( @.1, lastpos('/', @.1,L) )          /*determine the shortest  DIR  string. */
+if right(common, 1)=='/'  then common=left(common, max(0, length(common) - 1) )
+say 'common directory path: '  common            /* [↑]  handle trailing   /   delimiter*/
+                                                 /*stick a fork in it,  we're all done. */