很简单：前一个目录末尾是目录的话，最后是否带/是有区别的。
具体看测试：
# usr @ the-pc in ~/cptest02 [2:28:02] $ ll 总用量 0 # usr @ the-pc in ~/cptest02 [2:28:03] $ ll ../cptest01/ 总用量 4 -rw-rw-r-- 1 usr usr 0 10月 11 02:23 11111file drwxrwxr-x 2 usr usr 4096 10月 11 02:23 pppp # usr @ the-pc in ~/cptest02 [2:28:14] $ rsync -av ../cptest01/ ./ sending incremental file list ./ 11111file pppp/ pppp/adadasd.file sent 187 bytes received 57 bytes 488.00 bytes/sec total size is 0 speedup is 0.00 # usr @ the-pc in ~/cptest02 [2:28:33] $ ll 总用量 4 -rw-rw-r-- 1 usr usr 0 10月 11 02:23 11111file drwxrwxr-x 2 usr usr 4096 10月 11 02:23 pppp # usr @ the-pc in ~/cptest02 [2:28:46] $ rsync -av ../cptest01 ./ sending incremental file list cptest01/ cptest01/11111file cptest01/pppp/ cptest01/pppp/adadasd.file sent 201 bytes received 58 bytes 518.00 bytes/sec total size is 0 speedup is 0.00 # usr @ the-pc in ~/cptest02 [2:28:53] $ ll 总用量 8 -rw-rw-r-- 1 usr usr 0 10月 11 02:23 11111file drwxrwxr-x 3 usr usr 4096 10月 11 02:23 cptest01 drwxrwxr-x 2 usr usr 4096 10月 11 02:23 pppp # usr @ the-pc in ~/cptest02 [2:28:56] $
（shell是zsh，主题是ys。）