1、file1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
方法一：[[email protected]7 fh]# echo $(tr ‘ ‘ ‘+‘ <file1) | bc 55 方法二：[[email protected]7 fh]# x=$(($(tr ‘ ‘ ‘+‘ <file1))) && echo $x 55 方法三：[[email protected]7 fh]# x=$(tr ‘ ‘ ‘+‘ <file1) | python -c "print($x)" 55
2、处理字符串“xt.,l 1 jr#!$mn2 c*/fe3 uz4”，只保留其中的数字和空格
[[email protected]7 fh]# echo xt.,l 1 jr#mn2 c*/fe3 uz4 | grep -oP ‘\d|\s‘ | gawk ‘BEGIN{ORS=""}{print}END{print"\n"}‘ 1 2 3 4
3、将PATH变量每个目录显示在独立的一行
方法一：[[email protected]7 fh]# echo $PATH | awk ‘BEGIN{RS=":"}{print}‘
/usr/local/bin
/usr/bin
/usr/local/sbin
/usr/sbin
/home/fh/.local/bin
/home/fh/bin
方法二：
[[email protected]7 fh]# echo $PATH | tr ":" "\n"
/usr/local/bin
/usr/bin
/usr/local/sbin
/usr/sbin
/home/fh/.local/bin
/home/fh/bin
4、删除指定文件的空行
sed -i ‘/^$/d‘ file
5、将文件中每个单词（字母）显示在独立的一行，并无空行
[[email protected]7 fh]# cat testfile2
chen +sljfl s
[[email protected]7 fh]# gawk ‘BEGIN{RS=" "}{print}‘ testfile2 | sed ‘/^$/d‘
chen
+sljfl
s
[[email protected]7 fh]# grep -oP "." testfile2 | sed ‘/^ *$/d‘
c
h
e
n
+
s
l
j
f
l
s
6、创建用户gentoo，附加组为bin和root，默认shell为/bin/csh，注释信息为"Gentoo Distribution"
[[email protected]7 fh]# useradd -G bin,root -s /bin/csh -c "Gentoo Distribution" gentoo [[email protected]7 fh]# grep gentoo /etc/passwd gentoo:x:1002:1002:Gentoo Distribution:/home/gentoo:/bin/csh
7、将/etc/issue文件中的内容转换为大写后保存至/tmp/issue.out文件中
方法一： [[email protected]7 fh]# tr ‘[a-z]‘ ‘[A-Z]‘ < /etc/issue > /tmp/issue.out && cat /tmp/issue.out \S KERNEL \R ON AN \M 方法二： [[email protected]7 fh]# sed ‘s/[a-z]/\u&/g‘ /etc/issue > /tmp/issue.out && cat /tmp/issue.out \S KERNEL \R ON AN \M
问题扩展：将/etc/issue文件中的每个单词的首（末）字母转换为大写（或小写）后保存至/tmp/issue.out文件中
首字母转大写： [[email protected]7 fh]# sed ‘s/\b[a-z]/\u&/g‘ /etc/issue > /tmp/issue.out && cat /tmp/issue.out \S Kernel \R On An \M 首字母转小写： [[email protected]7 fh]# sed ‘s/\b[A-Z]/\l&/g‘ /etc/issue > /tmp/issue.out && cat /tmp/issue.out \s kernel \r on an \m 末字母转小写： [[email protected]7 fh]# sed ‘s/[A-Z]\b/\l&/g‘ /etc/issue > /tmp/issue.out && cat /tmp/issue.out \s Kernel \r on an \m
8、将当前系统登录用户的信息转换为小写
[[email protected]7 ~]# w | tr ‘[A-Z]‘ ‘[a-z]‘ 06:15:58 up 2:39, 2 users, load average: 0.00, 0.01, 0.02 user tty from login@ idle jcpu pcpu what fh pts/0 172.18.21.244 05:16 3:10 0.15s 0.05s sshd: fh [priv] root pts/1 172.18.21.244 06:12 6.00s 0.00s 0.00s w [[email protected]7 ~]# w | sed ‘s/[A-Z]/\l&/g‘ 06:16:15 up 2:39, 2 users, load average: 0.00, 0.01, 0.02 user tty from login@ idle jcpu pcpu what fh pts/0 172.18.21.244 05:16 3:27 0.15s 0.05s sshd: fh [priv] root pts/1 172.18.21.244 06:12 7.00s 0.00s 0.00s w
9、将/root/下文件列表，显示成一行，并文件名之间用空格隔开
[[email protected]7 ~]# ls -a | gawk ‘BEGIN{ORS=" "}{print}‘
. .. .bash_history .bash_logout .bash_profile .bashrc .cshrc .tcshrc anaconda-ks.cfg tmpfile
[[email protected]7 ~]# ls -a | tr ‘\n‘ ‘ ‘
. .. .bash_history .bash_logout .bash_profile .bashrc .cshrc .tcshrc anaconda-ks.cfg tmpfile
10、创建下面的用户、组和组成员关系
名字为admins 的组
[[email protected]7 fh]# groupadd admins [[email protected]7 fh]# grep admins /etc/group admins:x:1003:
用户natasha，使用admins 作为附属组
[[email protected]7 fh]# useradd -G admins natasha [[email protected]7 fh]# groups natasha natasha : natasha admins
用户harry，也使用admins 作为附属组
[[email protected]7 fh]# useradd -G admins harry [[email protected]7 fh]# groups harry natasha : harry admins
用户sarah，不可交互登录系统，且不是admins 的成员，natasha，harry，sarah密码都是centos
[[email protected]7 fh]# useradd -s /sbin/nologin sarah [[email protected]7 fh]# groups sarah sarah : sarah
[[email protected] fh]# echo ‘centos‘ | passwd --stdin natasha Changing password for user natasha. passwd: all authentication tokens updated successfully. [[email protected] fh]# echo ‘centos‘ | passwd --stdin harry Changing password for user harry. passwd: all authentication tokens updated successfully. [[email protected] fh]# echo ‘centos‘ | passwd --stdin sarah Changing password for user sarah. passwd: all authentication tokens updated successfully.
时间： 2024-10-16 14:15:03