课堂练习：
1、显示/var目录下所有以l开头，以一个小写字母结尾，且中间出现至少一位数字的文件和目录
[root@centos6 ~]# ls /var/l*[[:digit:]]*[[:lower:]] ls: cannot access /var/l*[[:digit:]]*[[:lower:]]: No such file or directory [root@centos6 ~]# touch /var/l5x [root@centos6 ~]# ls /var/l*[[:digit:]]*[[:lower:]] /var/l5x
2、显示/etc目录下以任意一位数字开头，且以非数字结尾的文件或目录
[root@centos6 ~]# ls /etc/[[:digit:]]*[^[:digit:]] ls: cannot access /etc/[[:digit:]]*[^[:digit:]]: No such file or directory [root@centos6 ~]# touch /etc/7abc [root@centos6 ~]# ls /etc/[[:digit:]]*[^[:digit:]] /etc/7abc
3、显示/etc目录下以非字母开头，后面跟了一个字母及其它任意长度任意字符的文件和目录
[root@centos6 ~]# ls -d /etc/[^[:alpha:]][[:alpha:]]* /etc/7abc
4、显示/etc目录下所有以m开头以非数字结尾的文件或目录
[root@centos6 ~]# ls -d /etc/m*[^0-9] /etc/magic /etc/mail.rc /etc/man.config /etc/mime.types /etc/modprobe.d /etc/mtab /etc/my.cnf /etc/mailcap /etc/makedev.d /etc/maven /etc/mke2fs.conf /etc/motd /etc/mtools.conf
5、显示/etc目录下，所有以.d结尾的文件或目录
[root@centos6 ~]# ls -d /etc/*.d /etc/bash_completion.d /etc/init.d /etc/modprobe.d /etc/rc0.d /etc/rc6.d /etc/setuptool.d /etc/chkconfig.d /etc/latrace.d /etc/oddjobd.conf.d /etc/rc1.d /etc/rc.d /etc/statetab.d /etc/cron.d /etc/ld.so.conf.d /etc/pam.d /etc/rc2.d /etc/request-key.d /etc/sudoers.d /etc/depmod.d /etc/logrotate.d /etc/popt.d /etc/rc3.d /etc/rsyslog.d /etc/sysctl.d /etc/dnsmasq.d /etc/lsb-release.d /etc/prelink.conf.d /etc/rc4.d /etc/rwtab.d /etc/xinetd.d /etc/dracut.conf.d /etc/makedev.d /etc/profile.d /etc/rc5.d /etc/sane.d /etc/yum.repos.d
6、显示/etc目录下，所有以.conf结尾，且以m,n,r,p开头的文件或目录
[root@centos6 ~]# ls -d /etc/[mnrp]*.conf /etc/mke2fs.conf /etc/nsswitch.conf /etc/pm-utils-hd-apm-restore.conf /etc/readahead.conf /etc/rsyslog.conf /etc/mtools.conf /etc/ntp.conf /etc/pnm2ppa.conf /etc/request-key.conf /etc/nfsmount.conf /etc/pbm2ppa.conf /etc/prelink.conf /etc/resolv.conf
作业：
1、将/etc/issue文件中的内容转换为大写后保存至/tmp/issue.out文件中
[root@centos6 ~]# cat /etc/issue | tr 'a-z' 'A-Z' > /tmp/issue.out [root@centos6 ~]# cat !$ cat /tmp/issue.out CENTOS RELEASE 6.8 (FINAL) KERNEL \R ON AN \M TTY IS \L DATE IS \D HOSTNAME IS \N
2、将当前系统登录用户的信息转换为大写后保存至/tmp/who.out文件中
[root@centos6 ~]# who | tr 'a-z' 'A-Z' > /tmp/who.out [root@centos6 ~]# cat !$ cat /tmp/who.out ROOT PTS/0 2016-07-30 19:26 (172.18.19.236)
3、一个linux用户给root发邮件，要求邮件标题为“help”，邮件正文如下：
Hello,I am 用户名，the system version is here，pleasehelp me to check it，thanks！
[root@centos6 ~]# mail -s help wang Hello, I am wang, the system version is here, pleasehelp me to check it, thanks! . EOT [root@centos6 ~]# su - wang [wang@centos6 ~]$ mail Heirloom Mail version 12.4 7/29/08. Type ? for help. "/var/spool/mail/wang": 2 messages 2 new >N 1 root Sat Jul 30 20:59 18/662 "help" N 2 root Sat Jul 30 20:59 18/662 "help" & 1 Message 1: From root@centos6.localdomain Sat Jul 30 20:59:41 2016 Return-Path: <root@centos6.localdomain> X-Original-To: wang Delivered-To: wang@centos6.localdomain Date: Sat, 30 Jul 2016 20:59:41 +0800 To: wang@centos6.localdomain Subject: help User-Agent: Heirloom mailx 12.4 7/29/08 Content-Type: text/plain; charset=us-ascii From: root@centos6.localdomain (root) Status: R Hello, I am wang, the system version is here, pleasehelp me to check it, thanks! &
4、将/root/下文件列表，显示成一行，并以文件名之间用空格隔开
[root@centos6 ~]# ls -a | tr '\n' ' ' . .. .abrt anaconda-ks.cfg .bash_history .bash_logout .bash_profile .bashrc bc .cache .config .cshrc .dbus dead.letter Desktop Documents Downloads edrawmax-cn.exe .esd_auth file1 .gconf .gconfd .gnome2 .gnote .gnupg .gtk-bookmarks .gvfs .ICEauthority .imsettings.log install.log install.log.syslog .local Music .nautilus Pictures Public .pulse .pulse-cookie root.out .ssh .tcshrc Templates tr Videos .viminfo [root@centos6 ~]#
5、file文件的内容为：“1 2 3 4 5 6 7 8 9 10” 计算出所有数字的总和
[root@centos6 ~]# cat file1 1 2 3 4 5 6 7 8 9 10 [root@centos6 ~]# cat file1 |xargs|sed 's/ /+/g'|bc 55 [root@centos6 ~]# cat file1 1 2 3 4 5 6 7 8 9 10 [root@centos6 ~]# cat file1|tr ' ' '+' |bc 55
6、删除Windows文本文件中的"^M"字符
[root@centos6 ~]# cat -A file4.txt a^M$ b^M$ c^M$ d^M$ f^M$ g[root@centos6 ~]# tr -d '\r' < file4.txt > file5.txt [root@centos6 ~]# cat -A file5.txt a$ b$ c$ d$ f$ g[root@centos6 ~]#
7、处理字符串“xt.,1 1 jr#!$mn2 c*/fe3 uz4 ”,只保留其中的数字和空格
[root@centos6 ~]# echo "xt.,1 1 jr#bcmn2 c*/fe3 uz4" | tr -d '[[:alpha:]][[:punct:]]' 1 1 2 3 4
8、将PATH变量每个目录显示在独立的一行
[root@centos6 ~]# echo $PATH |tr ':' '\012' /usr/lib64/qt-3.3/bin /usr/local/sbin /usr/local/bin /sbin /bin /usr/sbin /usr/bin /root/bin
9、删除指定文件的空行
[root@centos6 ~]# cat file2 a b c [root@centos6 ~]# sed -i '/^$/d' file2 [root@centos6 ~]# cat file2 a b c
10、将文件中每个单词（字母）显示在独立的一行，并无空行
[root@centos6 ~]# cat file6 how are you! how old are you! [root@centos6 ~]# cat file6 |tr ' ' '\n' how are you! how old are you!
原创文章，作者：Aleen，如若转载，请注明出处：http://www.178linux.com/26882
