Mkdir的“-p”选项

Question

mkdir -p cmps012m/lab1

Answer 1

手册页是你能找到的最好的信息来源...并且就在您的指尖:man mkdir生成关于-p开关：

-p, --parents
    no error if existing, make parent directories as needed

用例示例：假设我想创建目录hello/goody，但是没有：

$mkdir hello/goodbye
mkdir:cannot create directory 'hello/goodbye': No such file or directory
$mkdir -p hello/goodbye
$

-p同时创建了hello和goody

这意味着该命令将创建满足请求所需的所有目录，在该目录存在的情况下不会返回任何错误。

关于rlidwka，Google对缩略词有很好的记忆：）。我的搜索返回了以下内容：http://www.cs.cmu.edu/~help/afs/afs_acls.html

 Directory permissions

l (lookup)
    Allows one to list the contents of a directory. It does not allow the reading of files. 
i (insert)
    Allows one to create new files in a directory or copy new files to a directory. 
d (delete)
    Allows one to remove files and sub-directories from a directory. 
a (administer)
    Allows one to change a directory's ACL. The owner of a directory can always change the ACL of a directory that s/he owns, along with the ACLs of any subdirectories in that directory. 

File permissions

r (read)
    Allows one to read the contents of file in the directory. 
w (write)
    Allows one to modify the contents of files in a directory and use chmod on them. 
k (lock)
    Allows programs to lock files in a directory. 

因此rlidwka意味着：所有权限打开。