command line - When would multiple `///` be used between sub-directories? - Ask Ubuntu

i digging through /var/log/plymouth-debug.log , spotted line:

[main.c:716] get_cache_file_for_mode:returning cache file '/var/lib/plymouth//boot-duration' 

i thought typo typed following , sure enough can have many /// between sub-directories , file name want. example:

rick@dell:~$ ls -la /var/lib/plymouth/boot-duration -rw-r--r-- 1 root root 2041 nov  3 21:39 /var/lib/plymouth/boot-duration ──────────────────────────────────────────────────────────────── rick@dell:~$ ls -la /var/lib/plymouth/////boot-duration -rw-r--r-- 1 root root 2041 nov  3 21:39 /var/lib/plymouth/////boot-duration ──────────────────────────────────────────────────────────────── rick@dell:~$ ls -la /var/lib//plymouth///boot-duration -rw-r--r-- 1 root root 2041 nov  3 21:39 /var/lib//plymouth///boot-duration 

under circumstances want use 2 or more // instead of single / separator?

this answered nicely gilles on @ unix & linux: how linux handle multiple consecutive path separators (/home////username///file)?

multiple slashes allowed , equivalent single slash. single unix specification (version 3), base definitions §3.266 pathname: “multiple successive slashes considered same 1 slash.”

there 1 exception: if pathname starts 2 slashes, may treated differently (ref: base definitions §4.11 pathname resolution). linux doesn't this, though applications might, , other unix-ish system (e.g. cygwin).

a trailing / @ end of pathname forces pathname refer directory. in (posix 1003.1-2001 (single unix v3) base definitions §4.11 pathname resolution, trailing / equivalent trailing /.. posix 1003.1-2008 (single unix v4) base definitions §4.12 removes requirement make equivalent /., in order cope non-existing directories (e.g. mkdir foo/ required work, whereas mkdir foo/. wouldn't — see rationale change).

for programs act on directory entry, if foo symbolic link directory, passing foo/ way make program act on directory instead of symbolic link.

¹ _{note applies pathname resolution only, i.e. when accessing files. filename manipulations may work differently. example basename , dirname ignore trailing slashes.}

in case, i'm assuming /// programming over-cautiousness (some dev using / join paths when have trailing or leading slashes respectively).