On Mon, Aug 08, 2011 at 03:41:52PM +0200, mhenn wrote: > Am 08.08.2011 15:22, schrieb Francky Leyn: > > On 8/8/2011 2:17 PM, mhenn wrote: > >> Am 08.08.2011 11:33, schrieb Francky Leyn: > >>> consider the following code: > >>> > >>> EXTENSION=jpg > >>> INPUT_FILES=*.$EXTENSION > >> > >> echo "$INPUT_FILES" #obviously wrong > >> #instead maybe > >> INPUT_FILES="$(ls *.$EXTENSION)"
They are both incorrect. If you want a list of all the files that match a glob, use an array to hold them: files=(*.$extension) Parameter expansion ($extension) happens before globbing (*.jpg), and the results will be placed into an array. Filenames with whitespace will be handled correctly. > > This worked when there were files. > > But when there were no matching files, it didn't. If you want the array to be empty when there are no matching files, then you must enable bash's nullglob option: shopt -s nullglob files=(*.$extension) See also http://mywiki.wooledge.org/BashFAQ/004 (checking/counting files) and http://mywiki.wooledge.org/BashFAQ/005 (arrays) and http://mywiki.wooledge.org/glob (globs) Using ls in a script is almost always wrong, unless you're simply dumping its output to a terminal for a human to read. Use globs instead.
