命令替换
使用命令执行的结果替换该命令
$(命令)
[root@51cto /]# echo "The current directory is $(pwd)" The current directory is /
[root@51cto ziqiang]# touch file-$(date +%Y-%m-%d-%H-%M-%S) [root@51cto ziqiang]# ls file-2018-05-26-04-05-25
也可以使用反引号实现命令替换
[root@51cto ziqiang]# touch file-`date +%Y-%m-%d-%H-%M-%S` [root@51cto ziqiang]# ls file-2018-05-26-04-12-40
bash 中 “ ” 弱引用 能够实现命令替换
‘ ’ 强引用 不能够实现命令替换
路径替换
mkdir命令，-v显示创建过程
[root@51cto ziqiang]# mkdir ./{a,b} -v mkdir: created directory `./a' mkdir: created directory `./b' [root@51cto ziqiang]# ls a b [root@51cto ziqiang]# mkdir ./{x,y}{t,p} -v mkdir: created directory `./xt' mkdir: created directory `./xp' mkdir: created directory `./yt' mkdir: created directory `./yp' [root@51cto ziqiang]# ls a b xp xt yp yt
-p递归创建
[root@51cto ziqiang]# mkdir ./{zz,yy}/a/b -pv mkdir: created directory `./zz' mkdir: created directory `./zz/a' mkdir: created directory `./zz/a/b' mkdir: created directory `./yy' mkdir: created directory `./yy/a' mkdir: created directory `./yy/a/b' [root@51cto ziqiang]# tree . . ├── yy │ └── a │ └── b └── zz └── a └── b 6 directories, 0 files
重定向和管道
