One or two dots (. or ..), OK, but what do three or more dots mean?

Question

Why does this work?

if [ -d "." ] ; then echo "ok"; else echo "nok"; fi
if [ -d ".." ] ; then echo "ok"; else echo "nok"; fi
if [ -d "..." ] ; then echo "ok"; else echo "nok"; fi
if [ -d "...." ] ; then echo "ok"; else echo "nok"; fi
if [ -d "nosuchdir" ] ; then echo "ok"; else echo "nok"; fi

Output:

ok
ok
ok
ok
nok

What is supposed to mean ... or .... in a shell env?

Means nothing (just another possible filename) to the shell itself. — Charles Duffy, May 19 '17 at 19:52
Related: [Three dots directory traversal with `mv`](http://stackoverflow.com/questions/17913715/three-dots-directory-traversal-with-mv) — Charles Duffy, May 19 '17 at 19:53
Related: [Unix terminal, “cd ..” for a specific number of directories](http://stackoverflow.com/q/41636778/2908724) — bishop, May 19 '17 at 19:55

bishop · Answer 1 · 2017-05-19T20:00:49.113

8

It means someone has created directories named ... and ..... Consider:

$ [ -d '...' ] && echo 'ok' || echo 'nok'
nok
$ mkdir ...
$ [ -d '...' ] && echo 'ok' || echo 'nok'
ok

edited May 19 '17 at 20:00

answered May 19 '17 at 19:53

bishop

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6

...unless the OP has badly mistagged their question and is actually running "Git Bash" or such on Windows, in which case `...` is equivalent to `../..`. – Charles Duffy May 19 '17 at 20:07
2

@CharlesDuffy This feature was incorporated into Windows 95 from Novel NetWare. It was not included into the Windows NT branch. So it has been more than ten years since the feature was last time in a supported Windows version (probably Windows ME). --- See https://devblogs.microsoft.com/oldnewthing/20160202-00/?p=92953 https://superuser.com/questions/480122/does-have-meaning-as-a-relative-pathname-edit-no#comment568496_480122 – pabouk - Ukraine stay strong Dec 16 '19 at 12:25

One or two dots (. or ..), OK, but what do three or more dots mean?

1 Answers1