Linux三剑客
awk
概要： 三剑客老大，擅长取列
语法格式： awk ‘ pattern {action} ‘ 参数：
| 参数 | 说明 |
|---|---|
| 打印 | |
| -F | 指定分隔符’[分隔符1分隔符2]’ |
| NR | 行号 |
| $0,$1,$NF | $0整行，$1第一列，$NF最后一行 |
| + | 多个分隔符看作为一个 |
使用示例：
- 打印出/etc/passwd文件中第一列所有的用户名
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> <span class="line">10</span> <span class="line">11</span> <span class="line">12</span> <span class="line">13</span> <span class="line">14</span> <span class="line">15</span> <span class="line">16</span> <span class="line">17</span> <span class="line">18</span> <span class="line">19</span> <span class="line">20</span> <span class="line">21</span> <span class="line">22</span> <span class="line">23</span> <span class="line">24</span> <span class="line">25</span> |
<span class="line">[root@ansheng ~]<span class="comment"># awk –F ” :” '{print $1}' /etc/passwd</span></span>
<span class="line">root</span>
<span class="line">bin</span>
<span class="line">daemon</span>
<span class="line">adm</span>
<span class="line">lp</span>
<span class="line">sync</span>
<span class="line">shutdown</span>
<span class="line">halt</span>
<span class="line">mail</span>
<span class="line">uucp</span>
<span class="line">operator</span>
<span class="line">games</span>
<span class="line">gopher</span>
<span class="line">ftp</span>
<span class="line">nobody</span>
<span class="line">dbus</span>
<span class="line">vcsa</span>
<span class="line">abrt</span>
<span class="line">haldaemon</span>
<span class="line">ntp</span>
<span class="line">saslauth</span>
<span class="line">postfix</span>
<span class="line">sshd</span>
<span class="line">tcpdump</span>
|
sed
概要： 文本处理工具，取行、替换、删除、新增、选取，字符的过滤
语法格式： sed [-nefri] “command” 输入文本
参数：
| 参数 | 说明 |
|---|---|
| -d | 删除 |
| -p | 打印 |
| -i | 改变文件内容 |
| s | 编辑替换 |
| -n | 取消默认输出 |
| g | 全部替换 |
使用示例：
- 打印出当前目录下的linux文件中的内容第3行
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> |
<span class="line">[root@ansheng ~]<span class="comment"># cat -n linux </span></span> <span class="line"> 1 linux</span> <span class="line"> 2 centos</span> <span class="line"> 3 miniux</span> <span class="line"> 4 nuix</span> <span class="line">[root@ansheng ~]<span class="comment"># sed -n '3p' linux </span></span> <span class="line">miniux</span> |
- 显示/etc/passwd文件的第一行到第五行
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> |
<span class="line">[root@ansheng ~]<span class="comment"># sed -n '5,10p' /etc/passwd</span></span> <span class="line">lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin</span> <span class="line">sync:x:5:0:sync:/sbin:/bin/sync</span> <span class="line">shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown</span> <span class="line">halt:x:7:0:halt:/sbin:/sbin/halt</span> <span class="line">mail:x:8:12:mail:/var/spool/mail:/sbin/nologin</span> <span class="line">uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin</span> |
- 删除当前目录下的file文件内容2到5行
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> 8 9 10 11 12 13 14 15 16 17 18 |
[root@ansheng ~]# cat file <span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> 8 9 10 [root@ansheng ~]# sed '2,5d' file <span class="line">1</span> 6 7 8 9 10 |
<span class="line">1</span> |
<span class="line">sed <span class="string">'/My/,/You/d'</span> datafile</span> |
删除包含”My”的行到包含”You”的行之间的行
<span class="line">1</span> |
<span class="line">sed <span class="string">'/My/,10d'</span> datafile</span> |
删除包含”My”的行到第十行的内容
- 将当前目录下的linux文件中包含ansheng的内容全部替换为redhat
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> 8 9 10 11 12 13 |
<span class="line">[root@ansheng ~]<span class="comment"># cat linux </span></span> <span class="line">linux</span> <span class="line">centos</span> <span class="line">miniux</span> <span class="line">nuix</span> <span class="line">ansheng</span> <span class="line">[root@ansheng ~]<span class="comment"># sed -i 's#ansheng#redhat#g' linux </span></span> <span class="line">[root@ansheng ~]<span class="comment"># cat linux </span></span> <span class="line">linux</span> <span class="line">centos</span> <span class="line">miniux</span> <span class="line">nuix</span> <span class="line">redhat</span> |
grep
概要： 过滤指定字符串
语法格式： grep [OPTIONS] PATTERN [FILE…] grep [OPTIONS] [-e PATTERN | -f FILE] [FILE…]
参数：
| 参数 | 说明 |
|---|---|
| -i | 不区分大小写 |
| -v | 排除指定字符串 |
| -E | 过滤多个字符串 |
| -n | 显示字符串所在文件中的行 |
| -o | 只输出匹配出来的字符串 |
| -A N | 匹配内容的后N行 |
| -B N | 匹配内容的前N行 |
| -C N | 匹配内容的前后N行 |
| –color=auto | 过滤出来的字符串以颜色显示 |
元字符
| 符号 | 说明 |
|---|---|
| . | 匹配任意单个字符 |
| [] | 匹配指定范围内的任意单个字符 |
| [^] | 匹配指定范围内的任意单个字符 |
字符集合
| 符号 | 说明 |
|---|---|
| [[:digit:]] | 数字 |
| [[:lower:]] | 小写字母 |
| [[:upper:]] | 大写字母 |
| [[:punct:]] | 标点符号 |
| [[:space:]] | 空白字符 |
| [[:alpha:]] | 所有字母 |
| [[:alnum:]] | 所有数字和字母 |
匹配次数（贪婪模式，尽可能长的去匹配）：
| 符号 | 说明 |
|---|---|
| * | 匹配其前面的字符任意次 |
| .* | 任意长度的任意字符 |
| ？ | 匹配其前面的字符一次或0次 |
| {m,n} | 匹配其前面的字符至少m次，至多n次 |
位置锚定：
| 符号 | 说明 |
|---|---|
| ^ | 锚定行首，此字符后面的任意内容必须出现在行首 |
| $ | 锚定行尾，此字符后面的任意内容必须出现在行尾 |
| ^$ | 空白行 |
| < | (\b)其后面的任意字符必须作为单词的首部出现 |
| > | (\b)其前面的任意字符必须作为单词的尾部出现 |
分组：
| 符号 | 说明 | |
|---|---|---|
| () | 分组 | |
| a | b | or，或者 |
使用示例：
- 过滤出当前目录下面的ett文件中包含”ansheng”的字符串，并且显示该字符串所在行。
<span class="line">1</span> 2 3 4 5 6 |
<span class="line">[root@anshenglinux ~]<span class="comment"># cat -n ett </span></span> <span class="line"> 1 linux</span> <span class="line"> 2 ansheng</span> <span class="line"> 3 Linux</span> <span class="line">[root@anshenglinux ~]<span class="comment"># grep -n "ansheng" ett </span></span> <span class="line">2:ansheng</span> |
- 过滤出当前目录下的”linux”文件中包含LINUX和linux的字符串
方法1：
<span class="line">1</span> 2 3 |
<span class="line">[root@anshenglinux ~]<span class="comment"># grep -E "linux|LINUX" ett </span></span> <span class="line">linux</span> <span class="line">LINUX</span> |
方法2：
<span class="line">1</span> 2 3 |
<span class="line">[root@anshenglinux ~]<span class="comment"># grep -i "linux" ett </span></span> <span class="line">linux</span> <span class="line">LINUX</span> |
- 排除当前目录下包含linux文件中包含“ansheng”的字符串
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> |
<span class="line">[root@anshenglinux ~]<span class="comment"># cat ett </span></span> <span class="line">linux</span> <span class="line">ansheng</span> <span class="line">LINUX</span> <span class="line">[root@anshenglinux ~]<span class="comment"># grep -v "ansheng" ett </span></span> <span class="line">linux</span> <span class="line">LINUX</span> |
其它命令
xargs
概要： 取前一个命令的输出作为另一个命令的参数
语法格式： | xargs Command file
使用示例：
- 删除/tmp下面的所有后缀为.sh的文件
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> |
<span class="line">[root@linux tmp]<span class="comment"># pwd </span></span> <span class="line">/tmp</span> <span class="line">[root@linux tmp]<span class="comment"># ls</span></span> <span class="line">a.sh b.sh c d</span> <span class="line">[root@linux tmp]<span class="comment"># find ./ -type f -name "*.sh"|xargs rm -f</span></span> <span class="line">[root@linux tmp]<span class="comment"># ls</span></span> <span class="line">c d</span> |
vi/vim
概要： 文本编辑器
语法格式： vim file
参数：
命令模式：
| 参数 | 说明 |
|---|---|
| i | 在光标所在字符前插入 |
| I | 在光标所在字符后插入 |
| a | 在光标所在字符后插入 |
| A | 在光标所在行尾插入 |
| o | 在光标下插入新行 |
| O | 在光标上插入新行 |
| gg | 到第一行 |
| GG | 到最后一行 |
| nG | 到第n行 |
| 0 | 移动到行首 |
| $ | 移动到行尾 |
| x | 删除光标所在处字符 |
| nx | 删除光标所在处后面N个字符 |
| dd | 删除或剪切光标所在行 |
| ddd | 删除或剪切光标下N行 |
| D | 删除光标所在出至行尾的内容 |
| yy | 复制当前行 |
| nyy | 复制当前行以下n行 |
| P/p | 粘贴光标所在行下或行上 |
| r | 替换光标所在处字符 |
| R | 从光标所在处开始替换字符，按Esc结束 |
| u | 取消上一步操作 |
| ZZ | 保存修改退出 |
编辑模式：
| 参数 | 说明 |
|---|---|
| set nu | 显示行号 |
| set nonu | 取消行号 |
| w | 保存 |
| q | 退出 |
| ！ | 强制 |
| n | 到第N行 |
| n1,n2d | 删除指定范围的行 |
| /string | 搜索指定字符串，搜索时忽略大小写：set ic，取消：set noic，n搜索指定字符串下一个出现的位置 |
| %s/源字符串/替换后的字符串/g | 全文替换s,g不询问是否替换 |
| n1,n2s/源字符串/替换后的字符串/g | 指定范围内替换 |
| r 文件/命令 | 把文件内容或者命令执行结果导入到当前光标所在处后面 |
| ！ 命令 | 查找命令所在路径 |
alias
概要： 查看或设置别名
语法格式： alias[别名]=[指令]
使用示例：
- 查看当前已设置的别名
<span class="line">1</span>
<span class="line">2</span>
<span class="line">3</span>
<span class="line">4</span>
<span class="line">5</span>
<span class="line">6</span>
<span class="line">7</span>
8
|
<span class="line">[root@ansheng ~]<span class="comment"># alias </span></span> <span class="line"><span class="built_in">alias</span> cp=<span class="string">'cp -i'</span></span> <span class="line"><span class="built_in">alias</span> l.=<span class="string">'ls -d .* --color=auto'</span></span> <span class="line"><span class="built_in">alias</span> ll=<span class="string">'ls -l --color=auto'</span></span> <span class="line"><span class="built_in">alias</span> ls=<span class="string">'ls --color=auto'</span></span> <span class="line"><span class="built_in">alias</span> mv=<span class="string">'mv -i'</span></span> <span class="line"><span class="built_in">alias</span> rm=<span class="string">'rm -i'</span></span> <span class="line"><span class="built_in">alias</span> <span class="built_in">which</span>=<span class="string">'alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'</span></span> |
- 请使用别名功能设置执行ansheng命令就输出“ansheng ansheng”
<span class="line">1</span> 2 3 |
<span class="line">[root@ansheng ~]<span class="comment"># alias ansheng="echo 'ansheng ansheng'"</span></span> <span class="line">[root@ansheng ~]<span class="comment"># ansheng</span></span> <span class="line">ansheng ansheng</span> |
高级应用：
- 请设置grep命令过滤出来的字符串都显示有颜色，并且在系统下次重启之后也生效
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> 8 9 10 11 12 |
[root@ansheng ~]# cat ett <span class="line">1</span> 2 3 4 5 [root@ansheng ~]# grep "3" ett 3 [root@ansheng ~]# echo "alias grep='grep --color=auto'" >> /etc/bashrc [root@ansheng ~]# source /etc/bashrc [root@ansheng ~]# grep "3" ett 3 |
/etc/bashrc是全局变量，用户变量请添加到自己家目录下面的“.bashrc”， 有些自己定义的别名，就可以放在自己家目录的.bashrc里，因为个人爱好问题，有些人不需要
unalias
概要： 取消别名
语法格式： unalias 别名
使用示例：
- 删除已设置的别名ansheng
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> 8 9 10 11 12 13 14 15 16 17 18 19 20 |
[root@ansheng ~]# alias alias cp='cp -i' alias l.='ls -d .* --color=auto' alias ll='ls -l --color=auto' alias ls='ls --color=auto' alias mv='mv -i' alias ansheng='echo wocao' alias rm='rm -i' alias which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde' [root@ansheng ~]# unalias ansheng <span class="line">[root@ansheng ~]<span class="comment"># alias </span></span> <span class="line"><span class="built_in">alias</span> cp=<span class="string">'cp -i'</span></span> <span class="line"><span class="built_in">alias</span> l.=<span class="string">'ls -d .* --color=auto'</span></span> <span class="line"><span class="built_in">alias</span> ll=<span class="string">'ls -l --color=auto'</span></span> <span class="line"><span class="built_in">alias</span> ls=<span class="string">'ls --color=auto'</span></span> <span class="line"><span class="built_in">alias</span> mv=<span class="string">'mv -i'</span></span> <span class="line"><span class="built_in">alias</span> rm=<span class="string">'rm -i'</span></span> <span class="line"><span class="built_in">alias</span> <span class="built_in">which</span>=<span class="string">'alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde'</span></span> [root@ansheng ~]# ansheng -bash: ansheng: command not found |
yum
概要： 安装或卸载软件
语法格式： yum [参数] [软件名]
参数：
| 参数 | 概述 |
|---|---|
| install | 安装 |
| remove | 卸载 |
| groupinstall | 安装软件组 |
| -y | 不提示 |
| update | 升级全部软件或升级指定软件 |
使用示例：
- 安装dhcp服务
<span class="line">1</span> <span class="line">2</span> <span class="line">3</span> <span class="line">4</span> <span class="line">5</span> <span class="line">6</span> <span class="line">7</span> <span class="line">8</span> <span class="line">9</span> <span class="line">10</span> <span class="line">11</span> <span class="line">12</span> <span class="line">13</span> <span class="line">14</span> <span class="line">15</span> <span class="line">16</span> <span class="line">17</span> <span class="line">18</span> <span class="line">19</span> <span class="line">20</span> <span class="line">21</span> <span class="line">22</span> <span class="line">23</span> <span class="line">24</span> <span class="line">25</span> 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 |
<span class="line">[root@ansheng ~]<span class="comment"># yum -y install dhcp</span></span> <span class="line">Loaded plugins: fastestmirror, security</span> <span class="line">Setting up Install Process</span> <span class="line">Loading mirror speeds from cached hostfile</span> <span class="line"> * base: mirrors.aliyun.com</span> <span class="line"> * extras: mirrors.aliyun.com</span> <span class="line"> * updates: mirrors.aliyun.com</span> <span class="line">Resolving Dependencies</span> <span class="line">--> Running transaction check</span> <span class="line">---> Package dhcp.x86_64 12:4.1.1-43.P1.el6.centos will be installed</span> <span class="line">--> Processing Dependency: portreserve <span class="keyword">for</span> package: 12:dhcp-4.1.1-43.P1.el6.centos.x86_64</span> <span class="line">--> Running transaction check</span> <span class="line">---> Package portreserve.x86_64 0:0.0.4-9.el6 will be installed</span> <span class="line">--> Finished Dependency Resolution</span> <span class="line">Dependencies Resolved</span> <span class="line">=======================================================================================</span> <span class="line"> Package Arch Version Repository Size</span> <span class="line">=======================================================================================</span> <span class="line">Installing:</span> <span class="line"> dhcp x86_64 12:4.1.1-43.P1.el6.centos base 819 k</span> <span class="line">Installing <span class="keyword">for</span> dependencies:</span> <span class="line"> portreserve x86_64 0.0.4-9.el6 base 23 k</span> <span class="line">Transaction Summary</span> <span class="line">=======================================================================================</span> <span class="line">Install 2 Package(s)</span> <span class="line">Total download size: 842 k</span> <span class="line">Installed size: 1.9 M</span> <span class="line">Downloading Packages:</span> <span class="line">(1/2): dhcp-4.1.1-43.P1.el6.centos.x86_64.rpm | 819 kB 00:00 </span> <span class="line">(2/2): portreserve-0.0.4-9.el6.x86_64.rpm | 23 kB 00:00 </span> <span class="line">---------------------------------------------------------------------------------------</span> <span class="line">Total 1.1 MB/s | 842 kB 00:00 </span> <span class="line">Running rpm_check_debug</span> <span class="line">Running Transaction Test</span> <span class="line">Transaction Test Succeeded</span> <span class="line">Running Transaction</span> <span class="line"> Installing : portreserve-0.0.4-9.el6.x86_64 1/2 </span> <span class="line"> Installing : 12:dhcp-4.1.1-43.P1.el6.centos.x86_64 2/2 </span> <span class="line"> Verifying : 12:dhcp-4.1.1-43.P1.el6.centos.x86_64 1/2 </span> <span class="line"> Verifying : portreserve-0.0.4-9.el6.x86_64 2/2 </span> <span class="line">Installed:</span> <span class="line"> dhcp.x86_64 12:4.1.1-43.P1.el6.centos </span> <span class="line">Dependency Installed:</span> <span class="line"> portreserve.x86_64 0:0.0.4-9.el6 </span> <span class="line">Complete!</span> |
- 卸载dhcp服务
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<span class="line">[root@ansheng ~]<span class="comment"># rpm -q dhcp</span></span> <span class="line">dhcp-4.1.1-43.P1.el6.centos.x86_64</span> <span class="line">[root@ansheng ~]<span class="comment"># yum -y remove dhcp</span></span> <span class="line">Loaded plugins: fastestmirror, security</span> <span class="line">Setting up Remove Process</span> <span class="line">Resolving Dependencies</span> <span class="line">--> Running transaction check</span> <span class="line">---> Package dhcp.x86_64 12:4.1.1-43.P1.el6.centos will be erased</span> <span class="line">--> Finished Dependency Resolution</span> <span class="line">Dependencies Resolved</span> <span class="line">=======================================================================================</span> <span class="line"> Package Arch Version Repository Size</span> <span class="line">=======================================================================================</span> <span class="line">Removing:</span> <span class="line"> dhcp x86_64 12:4.1.1-43.P1.el6.centos @base 1.9 M</span> <span class="line">Transaction Summary</span> <span class="line">=======================================================================================</span> <span class="line">Remove 1 Package(s)</span> <span class="line">Installed size: 1.9 M</span> <span class="line">Downloading Packages:</span> <span class="line">Running rpm_check_debug</span> <span class="line">Running Transaction Test</span> <span class="line">Transaction Test Succeeded</span> <span class="line">Running Transaction</span> <span class="line"> Erasing : 12:dhcp-4.1.1-43.P1.el6.centos.x86_64 1/1 </span> <span class="line"> Verifying : 12:dhcp-4.1.1-43.P1.el6.centos.x86_64 1/1 </span> <span class="line">Removed:</span> <span class="line"> dhcp.x86_64 12:4.1.1-43.P1.el6.centos </span> <span class="line">Complete!</span> <span class="line">[root@ansheng ~]<span class="comment"># rpm -q dhcp</span></span> <span class="line">package dhcp is not installed</span> |
rpm
概要： 安装.RPM结尾的软件
语法格式： rpm [参数] [文件]
参数：
| 参数 | 说明 |
|---|---|
| -i | 安装软件 |
| -U | 升级软件 |
| -v | 显示过程 |
| -q | 查询安装的软件信息 |
| -l | 显示安装文件所在路径 |
| –nodeps | 忽略软件包的依赖关系强行安装 |
| –force | 忽略软件包及文件的冲突 |
使用示例：
- 查看已安装的软件”http”的安装版本信息
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<span class="line">[root@ansheng ~]<span class="comment"># rpm -q httpd</span></span> <span class="line">httpd-2.2.15-39.el6.centos.x86_64</span> |
locate
概要： 根据locate数据库查找文件或目录，updatedb更新库
语法格式： locate 文件或目录名
使用示例：
- 查找文件名为“ifcfg-eth0”的文件
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<span class="line">[root@ansheng ~]<span class="comment"># locate ifcfg-eth0 </span></span> <span class="line">/etc/sysconfig/network-scripts/ifcfg-eth0</span> |
runlevel
概要： 查看当前操作系统的运行级别，init切换运行级别
语法格式： runlebel
使用示例：
- 查看当前操作系统的运行级别
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<span class="line">[root@ansheng ~]<span class="comment"># runlevel </span></span> <span class="line">N 3</span> |
