ls -F会在目录名后面加/:
-F, --classify[=WHEN] append indicator (one of */=>@|) to entries WHEN
但ls -d */是因为bash的expansion. 我们可以写个 ls.sh，其 echo $* 来证实这一点。
我们还可以如下，sadly我解释不动了：
$ ls -F dir-a/ dir-b/ file-c
$ t=*/; echo $t dir-a/ dir-b/
$ t='*/'; echo $t dir-a/ dir-b/
$ t="*/"; echo $t dir-a/ dir-b/
$ echo */ dir-a/ dir-b/
$ echo '*/' */
$ echo "*/" */
https://www.gnu.org/software/bash/manual/html_node/Shell-Expansions.html
The order of expansions is:
- brace expansion;
- tilde (~) expansion,
- parameter and variable expansion,
- arithmetic expansion,
- and command substitution (done in a left-to-right fashion);
- word splitting;
- filename expansion;
- and quote removal.