Linux管道及IO重定向小練習

1.統計/usr/bin目錄下的文件個數

[root@localhost ~]# ls /usr/bin | wc -l 1306 [root@localhost ~]#

2.取出當前系統上全部用戶的SHELL，要求，每種SHELL只顯示一次，而且按順序進行顯示

[root@localhost ~]# cut -d: -f7 /etc/passwd | sort -u /bin/bash /bin/nologin /bin/sync /bin/tcsh /sbin/halt /sbin/login /sbin/nologin /sbin/shutdown [root@localhost ~]#

3.思考：如何顯示/var/log目錄下每一個文件的內容類型？

[root@localhost ~]# file /var/log/* /var/log/acpid: ASCII text /var/log/anaconda.log: ASCII English text, with very long lines /var/log/anaconda.syslog: ASCII English text /var/log/anaconda.xlog: ASCII English text /var/log/audit: directory /var/log/boot.log: empty /var/log/boot.log.1: empty /var/log/boot.log.2: empty /var/log/boot.log.3: empty /var/log/boot.log.4: empty

4.取出/etc/inittab文件的第6行

[root@localhost ~]# head -6 /etc/inittab # # inittab This file describes how the INIT process should set up # the system in a certain run-level. # # Author: Miquel van Smoorenburg, <miquels@drinkel.nl.mugnet.org> # Modified for RHS Linux by Marc Ewing and Donnie Barnes [root@localhost ~]# head -6 /etc/inittab | tail -1 # Modified for RHS Linux by Marc Ewing and Donnie Barnes [root@localhost ~]#

5.取出/etc/passwd文件中倒數第9個用戶的用戶名和SHELL，顯示到屏幕上並將其保存至/tmp/uses文件中

[root@localhost ~]# tail -9 /etc/passwd zhangfengzhe10:x:1102:1102::/home/zhangfengzhe10:/bin/bash zhangfengzhe11:x:1103:1103::/home/zhangfengzhe11:/sbin/nologin zhangfengzheforsys:x:101:102::/home/zhangfengzheforsys:/bin/bash test1:x:1104:1104::/home/test1:/bin/bash mandriva:x:4004:3004::/home/mandriva:/bin/bash fedora:x:2003:2003:Fedora Commnuity:/home/fedora:/bin/tcsh hbase:x:102:103::/home/hbase:/bin/nologin openstack:x:4005:4005::/home/openstack:/bin/bash hive:x:5000:5000::/home/hive:/bin/bash [root@localhost ~]# tail -9 /etc/passwd | head -1 zhangfengzhe10:x:1102:1102::/home/zhangfengzhe10:/bin/bash [root@localhost ~]# tail -9 /etc/passwd | head -1 | cut -d: -f1,7 zhangfengzhe10:/bin/bash [root@localhost ~]# tail -9 /etc/passwd | head -1 | cut -d: -f1,7 | tee /tmp/users zhangfengzhe10:/bin/bash [root@localhost ~]# cat /tmp/users zhangfengzhe10:/bin/bash [root@localhost ~]#

6.顯示/etc目錄下全部以pa開頭的文件，並統計其個數

[root@localhost ~]# ls -ld /etc/pa*/ drwxr-xr-x 2 root root 4096 Mar 5 2012 /etc/pam.d/ drwxr-xr-x 2 root root 4096 Aug 17 2011 /etc/pam_pkcs11/ drwxr-xr-x 3 root root 4096 Aug 17 2011 /etc/pango/ [root@localhost ~]# ls -ld /etc/pa*/ | wc -l 3 [root@localhost ~]#

7.不使用文本編輯器，將alias cls=clear一行內容添加至當前用戶的.bashrc文件中

[root@localhost ~]# echo "alias cls='clear'" alias cls='clear' [root@localhost ~]# echo "alias cls='clear'" >> ~/.bashrc [root@localhost ~]# tail -1 ~/.bashrc alias cls='clear' [root@localhost ~]# tail ~/.bashrc alias cp='cp -i' alias mv='mv -i' # Source global definitions if [ -f /etc/bashrc ]; then . /etc/bashrc fi alias cls='clear' [root@localhost ~]#

LINUX的重要哲學思想：

組合小命令完成複雜功能。