A three code line solution demonstrated step by step under the Perl debugger: 

  DB<1>  $year = (localtime time)[5] + 1900;

  DB<2> print $year
2013
  DB<3>  @filenames = map {"file_name_$year" . sprintf "%02d", $_} (1.
+.11);

  DB<4> x  @filenames
0  'file_name_201301'
1  'file_name_201302'
2  'file_name_201303'
3  'file_name_201304'
4  'file_name_201305'
5  'file_name_201306'
6  'file_name_201307'
7  'file_name_201308'
8  'file_name_201309'
9  'file_name_201310'
10  'file_name_201311'
  DB<5> unshift  @filenames, "file_name_" . ($year -1) . "12";

  DB<6> x  @filenames
0  'file_name_201212'
1  'file_name_201301'
2  'file_name_201302'
3  'file_name_201303'
4  'file_name_201304'
5  'file_name_201305'
6  'file_name_201306'
7  'file_name_201307'
8  'file_name_201308'
9  'file_name_201309'
10  'file_name_201310'
11  'file_name_201311'
  DB<7>

[download]

Done!

In reply to Re: Year-month for file names by Laurent_R
in thread Year-month for file names by Anonymous Monk

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