Ubuntu – How to batch convert folder names from one date format to another

daterename

I have a large number of folders, named as dates like so:

10 Aug 2010  15 Sep 2010  20 Jun 2010  25 Jul 2010  6 Nov 2010
10 Sep 2010  16 Aug 2010  20 Mar 2010  26 Aug 2010  6 Oct 2010
11 Apr 2010  16 Jun 2010  21 Jun 2010  28 Aug 2010  7 Apr 2010
12 Aug 2010  16 Oct 2010  21 Mar 2010  28 Feb 2010  7 Aug 2010
13 May 2010  17 Apr 2010  22 Feb 2010  28 Jun 2010  7 Jun 2010
14 Aug 2010  17 Aug 2010  23 Jul 2010  28 Mar 2010  8 Apr 2010
14 Jun 2010  18 Aug 2010  24 Jul 2010  29 Mar 2010  8 Aug 2010
15 Aug 2010  19 Aug 2010  24 Nov 2010  30 Aug 2010  8 Jul 2010
15 Jul 2010  4 Apr 2010  25 Apr 2010  6 May 2010   8 Sep 2010

I want the date format to change to this:

2010-04-04  2010-05-03
2010-06-06  2010-07-02
2010-07-05  2010-09-01
2010-09-04  2010-09-05
2010-11-01

How can I batch rename a lot of folders from DD MMM YYYY to YYYY-MM-DD?

Best Answer

Somewhat to my own surprise, it looks like our old friend prename (a.k.a rename on some systems) can do that - with a little wrangling:

$ prename -vn -- '
  BEGIN{use Time::Piece};
  s/\d+ \w+ \d+/Time::Piece->strptime($&, "%d %b %Y")->strftime("%Y-%m-%d")/e
' *
10 Aug 2010 renamed as 2010-08-10
8 Sep 2010 renamed as 2010-09-08

Alternatively, using GNU date

dirs=( ?\ ???\ ???? ??\ ???\ ???? ) # matches D MMM YYYY and DD MMM YYYY

for d in "${dirs[@]}"; do mv -v -- "$d" "$(date '+%Y-%m-%d' -d "$d")"; done

Testing with an echo (equivalent to prename's -n flag):

$ for d in "${dirs[@]}"; do echo mv -v -- "$d" "$(date '+%Y-%m-%d' -d "$d")"; done
mv -v -- 8 Sep 2010 2010-09-08
mv -v -- 10 Aug 2010 2010-08-10

Note that parsing of dates can be locale dependent.

Related Question