Hi David, on Thursday, 2005-12-29 at 13:53:17, you wrote: > > $(ls *.jpg) > > ick! > > (incidentally, http://www.ruhr.de/home/smallo/award.html#ls)
Well, it's bad in two ways, and even the example on the above webpage is
wrong. For one thing, "ls" is useless here. For another, it will break
on spaces in filenames, unlike shell globbing:
| $ touch "foo bar.jpg"
| $ for f in *.jpg; do echo $f; done
| foo bar.jpg
| $ for f in `ls *.jpg`; do echo $f; done
| foo
| bar.jpg
| $ for f in `ls *.jpg`; do echo "$f"; done
| foo
| bar.jpg
The bottommost try shows that the comment "newbies will often forget the
quotes, too" is wrong -- it won't work either way. If you have to use
a program that outputs a filename per line like ls, use a read loop:
| $ ls *.jpg | while read f; do echo "$f"; done
| foo bar.jpg
The quotes are useless for "echo" here, but for other commands you'll
usually need them to keep the command form taking filenames with sapaces
as separate arguments.
cheers!
Matthias
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