The "for f in `ls * `; do" example is actually not useless. It has the quality that the loop will not run if there are no files, because ls produces no output.

The "for f in `ls * `; do" example is actually not useless. It has the quality that the loop will not run if there are no files, because ls produces no output. Compare: $ for i in `ls * 2>/dev/null` do cat $i done $ $ for i in * do cat $i done cat: *: No such file or directory Imagine that instead of cat we have a large, complex, expensive loop and don't want to pass a useless '*' to it if we can avoid it.