Reber's Blog

只会一点点编程、只会一点点渗透


Linux 之文本处理

这里介绍3种方式:awk、grep、sed

0x00 awk处理文本(最常用)

作用:awk对数据以行分析并生成报告时显得很强大,它将行进行切片,再处理分开的切片,可对格式化的数据重新进行格式化  
awk命令格式:awk [F filed-separator] 'commands' input-fiel(s)  
参数-F:可以添加任意的分割符,比较重要  
awk工作流程是这样的:  
读入有'\n'换行符分割的一条记录,然后将记录按-F指定的域分隔符划分域,$0则表示所有域,$1表示第一个域,$n表示第n个域。默认域分隔符是"空白键" 或 "[tab]键"。
  • 入门示例:
[wyb@localhost temp]$ head -n 5 /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
[wyb@localhost temp]$ head -n 5 /etc/passwd | awk -F ':' '{print $1}' #输出第1列,域分隔符为:
root
bin
daemon
adm
lp
[wyb@localhost temp]$ head -n 5 /etc/passwd | awk -F ':'  '{pri
nt "id:"$1"\tshell:"$7}' #输出第1、7列且给予列名
id:root shell:/bin/bash
id:bin  shell:/sbin/nologin
id:daemon       shell:/sbin/nologin
id:adm  shell:/sbin/nologin
id:lp   shell:/sbin/nologin
[wyb@localhost temp]$ head -n 5 /etc/passwd | awk -F ':'  'BEGIN {print "====begin====="} {print "id:"$1"\tshell:"$7} END {print "====end===="}'
====begin=====
id:root shell:/bin/bash
id:bin  shell:/sbin/nologin
id:daemon       shell:/sbin/nologin
id:adm  shell:/sbin/nologin
id:lp   shell:/sbin/nologin
====end====
[wyb@localhost temp]$ awk -F: '/root/' /etc/passwd #搜索含有root关键字的所有行
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin
[wyb@localhost temp]$ awk -F: '/root/{print $7}' /etc/passwd #匹配root并输出对应shell
/bin/bash
/sbin/nologin
[wyb@localhost temp]$ awk -F: '/^root/' /etc/passwd #匹配以root开头的行
root:x:0:0:root:/root:/bin/bash
  • 内置变量:
  • awk编程:

    • 变量和赋值:
    [wyb@localhost temp]$ head -n 5 /etc/passwd | awk -F ':'  'BEGIN {count=0} {count++; print "username:"$1} END {print "count:"count}'
    username:root
    username:bin
    username:daemon
    username:adm
    username:lp
    count:5
    [wyb@localhost ~]$ ls -l aaa/ettercap-0.8.2 | awk 'BEGIN {size=0;} {size=size+5;} END {print "[end]size is:",size,"byte"}'
    [end]size is: 160 byte
    [wyb@localhost ~]$ ls -l aaa/ettercap-0.8.2 | awk 'BEGIN {size=0;} {size=size+5;} END {print "[end]size is:",size/1024/1024,"M"}'
    [end]size is: 0.000152588 M
    
    • 条件语句:
    [wyb@localhost ~]$ head -n 6 /etc/passwd | awk -F ':' '{if($1=="root") print "root bash is:"$7}'
    root bash is:/bin/bash
    [wyb@localhost ~]$ 
    

0x01 Grep处理文本

匹配到时输出一行

  • 常用参数:nrABC
[wyb@localhost ~]$ grep root /etc/passwd #查找root这个字符
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin
[wyb@localhost ~]$ grep -n root /etc/passwd #查找root字符串并输出所在行数
1:root:x:0:0:root:/root:/bin/bash
11:operator:x:11:0:operator:/root:/sbin/nologin
[wyb@localhost ~]$ grep -n root /etc/passwd --color #给字符串不同颜色
1:root:x:0:0:root:/root:/bin/bash
11:operator:x:11:0:operator:/root:/sbin/nologin
[wyb@localhost temp]$ ls
aa  b.txt
[wyb@localhost temp]$ grep -r -n root /home/wyb/temp/ --color #在temp目录及子目录查找字符串root
/home/wyb/temp/b.txt:4:sdkrootwe
/home/wyb/temp/b.txt:6:fsdkfjroot
/home/wyb/temp/b.txt:9:root
/home/wyb/temp/aa/a.txt:1:1     root    12sf34s56
[wyb@localhost temp]$ grep -r -n "^root" /etc/passwd --color #正则查找字符串root
1:root:x:0:0:root:/root:/bin/bash
[wyb@localhost temp]$ grep -r -n "root" /etc/passwd --color -c #匹配的行的数
2
[wyb@localhost temp]$ ps aux | grep "^wyb"
wyb        2185  0.0  0.1  99952  1840 ?        S    16:33   0:02 sshd: wyb@pts/0  
wyb        2186  0.0  0.1 108464  1944 pts/0    Ss   16:33   0:00 -bash
wyb        3229  2.0  0.1 110232  1136 pts/0    R+   18:27   0:00 ps aux
wyb        3230  0.0  0.0 103244   828 pts/0    S+   18:27   0:00 grep ^wyb
[wyb@localhost temp]$ ps aux | grep ora
wyb        3233  0.0  0.0 103244   828 pts/0    S+   18:28   0:00 grep ora

0x02 sed处理文本

* 处理大文本很好用,上几十万、上百万行的数据
* sed主要以行为单位,可以将数据行进行替换、删除、新增、选取等
* sed语法 参数 动作 文件
* -n只把匹配到的输出
* 主要参数是:
    * a 在下面插入数据
    * d 删除
    * i 在上面插入数据
    * p 输出数据
    * c 替换字符串,后面可跟字符串,字符串替换n1到n2之间的行<br/>
      s 替换字符串,通常搭配正则
  • 字符的删除
[wyb@localhost aa]$ nl a.txt | sed '3,8d' #不输出3-8行
     1  1     root      12sf34s56
     2  2     admin     ksdjfiweurf
     9  9     candy     kd89943
[wyb@localhost aa]$ nl a.txt | sed '3,$d' #从第三行删到最后一行
     1  1     root      12sf34s56
     2  2     admin     ksdjfiweurf
[wyb@localhost aa]$ nl a.txt | sed '/root/d' #正则删除带root的行
     2  2     admin     ksdjfiweurf
     3  3     dome      skd89453
     4  4     tomkd     3jkke34
     5  5     jarry     sdkj89ry4
     6  6     canki     sdkj834
     7  7     lola      er8f7734
     8  8     marry     j8jkf78
     9  9     candy     kd89943
  • a插入字符
[wyb@localhost aa]$ nl a.txt | sed '2a aaaaaa' | head -n 5 #在第二行下面插入一行字符串aaaaaa
     1  1     root      12sf34s56
     2  2     admin     ksdjfiweurf
aaaaaa
     3  3     dome      skd89453
     4  4     tomkd     3jkke34
[wyb@localhost aa]$ nl a.txt | sed '2i aaaaaa' | head -n 5 #在第二行上面插入一行字符串aaaaaa
     1  1     root      12sf34s56
aaaaaa
     2  2     admin     ksdjfiweurf
     3  3     dome      skd89453
     4  4     tomkd     3jkke34
[wyb@localhost aa]$ nl a.txt | sed '2i aaaaaa \ #增加多行用\
bbbbb\
ccccc\
dddddd' | head -n 7
     1  1     root      12sf34s56
aaaaaa 
bbbbb
ccccc
dddddd
     2  2     admin     ksdjfiweurf
     3  3     dome      skd89453
  • p输出字符
[wyb@localhost aa]$ nl a.txt | sed '2,5p'
     1  1     root      12sf34s56
     2  2     admin     ksdjfiweurf
     2  2     admin     ksdjfiweurf
     3  3     dome      skd89453
     3  3     dome      skd89453
     4  4     tomkd     3jkke34
     4  4     tomkd     3jkke34
     5  5     jarry     sdkj89ry4
     5  5     jarry     sdkj89ry4
     6  6     canki     sdkj834
     7  7     lola      er8f7734
     8  8     marry     j8jkf78
     9  9     candy     kd89943
[wyb@localhost aa]$ nl a.txt | sed -n '2,5p' #加-n去除其余行
     2  2     admin     ksdjfiweurf
     3  3     dome      skd89453
     4  4     tomkd     3jkke34
     5  5     jarry     sdkj89ry4
[wyb@localhost aa]$ nl a.txt | sed -n '/root/p' #正则匹配root
     1  1     root      12sf34s56
[wyb@localhost bbb]$ nl /etc/passwd | sed -n '/root/{s/root/111111/;p}' #查找root,然后将行中的第一个root替换为abcdefg  -n代表不输出所有的
     1  111111:x:0:0:root:/root:/bin/bash
    11  operator:x:11:0:operator:/111111:/sbin/nologin
  • c和s替换字符
[wyb@localhost aa]$ nl a.txt | sed '2,5c aaaaaa' #将第2-5行替换
     1  1     root      12sf34s56
aaaaaa
     6  6     canki     sdkj834
     7  7     lola      er8f7734
     8  8     marry     j8jkf78
     9  9     candy     kd89943
[wyb@localhost aa]$ nl /etc/passwd | sed -n '/root/{s/root/1111/g;p}'查找root,然后将全局的root替换为1111
     1  1111:x:0:0:1111:/1111:/bin/bash
    11  operator:x:11:0:operator:/1111:/sbin/nologin
[wyb@localhost aa]$ nl /etc/passwd | sed -n '1,3{s/root/1111/g;p}'前五行查找root,然后将全局的root替换为1111
     1  1111:x:0:0:1111:/1111:/bin/bash
     2  bin:x:1:1:bin:/bin:/sbin/nologin
     3  daemon:x:2:2:daemon:/sbin:/sbin/nologin
[wyb@localhost aa]$ nl /etc/passwd | sed -n '1,5{s/root/1111/g;p;q}'前五行查找root,然后将整行的root替换为1111,查找到一个就退出
     1  1111:x:0:0:1111:/1111:/bin/bash
  • 实例
[wyb@localhost aa]$ ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:0C:29:56:B4:10  
          inet addr:192.168.63.131  Bcast:192.168.63.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe56:b410/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11732 errors:0 dropped:0 overruns:0 frame:0
          TX packets:7223 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1148256 (1.0 MiB)  TX bytes:1192150 (1.1 MiB)


[wyb@localhost aa]$ ifconfig eth0 | grep 'inet add' 
          inet addr:192.168.63.131  Bcast:192.168.63.255  Mask:255.255.255.0
[wyb@localhost aa]$ ifconfig eth0 | grep 'inet add' | sed 's/Bcast.*$//g'
          inet addr:192.168.63.131  
[wyb@localhost aa]$ 

[wyb@localhost aa]$ nl /etc/passwd | sed '3,$d'
     1  root:x:0:0:root:/root:/bin/bash
     2  bin:x:1:1:bin:/bin:/sbin/nologin
[wyb@localhost aa]$ nl /etc/passwd | sed '3,$d' | sed -n 's/bash/buleshell/p'
     1  root:x:0:0:root:/root:/bin/buleshell

[wyb@localhost aa]$ nl /etc/passwd | sed -e '3,$d' -e 's/bash/buleshell/p'
     1  root:x:0:0:root:/root:/bin/buleshell
     1  root:x:0:0:root:/root:/bin/buleshell
     2  bin:x:1:1:bin:/bin:/sbin/nologin
[wyb@localhost aa]$ 


[wyb@localhost aa]$ nl /etc/passwd | sed -e '3,$d' -e 's/bash/buleshell/p'
     1  root:x:0:0:root:/root:/bin/buleshell
     1  root:x:0:0:root:/root:/bin/buleshell
     2  bin:x:1:1:bin:/bin:/sbin/nologin
[wyb@localhost aa]$ nl /etc/passwd | sed -e '3,$d' -e 's/bash/buleshell/p' > test.txt
[wyb@localhost aa]$ cat test.txt 
     1  root:x:0:0:root:/root:/bin/buleshell
     1  root:x:0:0:root:/root:/bin/buleshell
     2  bin:x:1:1:bin:/bin:/sbin/nologin