Brace expansion using incrementers sometimes produces unexpected results with regard to padding.
Note the following 4 examples not using incrementers: bash> echo {0..9} 0 1 2 3 4 5 6 7 8 9 bash> echo {00..9} 00 01 02 03 04 05 06 07 08 09 bash> echo {0..09} 00 01 02 03 04 05 06 07 08 09 bash> echo {00..09} 00 01 02 03 04 05 06 07 08 09 All of the results above are as expected. Now note these similar expansions with incrementers added: bash> echo {0..9..2} 0 2 4 6 8 bash> echo {00..9..2} 00 02 04 06 08 bash> echo {0..09..2} 00000 00002 00004 00006 00008 bash> echo {00..09..2} 00000 00002 00004 00006 00008 The first two are as expected, but the last two have unexpected additional padding. These examples were using: bash> bash --version GNU bash, version 4.0.35(1)-release (i586-suse-linux-gnu) Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>