一個非常有用的命令，主要用來提取各種各樣的數據。

cut -cchars file
如：
 -c5     提取第5個字符
      -c5-    提取第5個字符以后的字符
      -c1,5,12 提取多個字符，中間用“,”符號隔開
      -c5-14 提取第5個字符到第14個字符間的字符

[service@dsg tmp]$ cat f.txt
service pts/0       Oct 9 20:27 (211.95.114.235)
service pts/1       Oct 9 21:06 (218.80.203.242)
service pts/2       Oct 9 14:35 (218.80.203.242)
service pts/3       Oct 9 21:07 (218.80.213.242)
service pts/4       Oct 9 21:07 (218.80.213.242)
service pts/5       Oct 9 21:45 (58.31.205.19)
[service@dsg tmp]$ cut -c5 f.txt
i
i
i
i
i
i
[service@dsg tmp]$ cut -c5- f.txt 
ice pts/0       Oct 9 20:27 (211.95.114.235)
ice pts/1       Oct 9 21:06 (218.80.203.242)
ice pts/2       Oct 9 14:35 (218.80.203.242)
ice pts/3       Oct 9 21:07 (218.80.213.242)
ice pts/4       Oct 9 21:07 (218.80.213.242)
ice pts/5       Oct 9 21:45 (58.31.205.19)
[service@dsg tmp]$ cut -c1,5,14 f.txt
si0
si1
si2
si3
si4
si5

------------------------------
cut -d -f
-d, --delimiter=DELIM
            use DELIM instead of TAB for field delimiter

-f, --fields=LIST
            output only these fields; also print any line that contains no
            delimiter character, unless the -s option is specified

-d -f 主要用來從某中分隔符中提取數據
如：
[service@dsg tmp]$ cat f.txt
service1:pts/0:Oct 9 20:27: (211.95.114.235)
service2:pts/1:Oct 9 21:06: (218.80.203.242)
service3:pts/2:Oct 9 14:35: (218.80.203.242)
service4:pts/3:Oct 9 21:07: (218.80.213.242)
service5:pts/4:Oct 9 21:07: (218.80.213.242)
service6:pts/5:Oct 9 21:45: (58.31.205.19)
[service@dsg tmp]$ cut -d: -f1 f.txt
service1
service2
service3
service4
service5
service6
[service@dsg tmp]$ cut -d: -f2 f.txt
pts/0
pts/1
pts/2
pts/3
pts/4
pts/5
[service@dsg tmp]$ cut -d: -f3 f.txt
Oct 9 20
Oct 9 21
Oct 9 14
Oct 9 21
Oct 9 21
Oct 9 21
[service@dsg tmp]$ cut -d: -f5 f.txt
(211.95.114.235)
(218.80.203.242)
(218.80.203.242)
(218.80.213.242)
(218.80.213.242)
(58.31.205.19)
[service@dsg tmp]$ cut -d: -f9 f.txt


[service@dsg tmp]$ cut -d: -f1,4 f.txt #提取1和4列數據
service1:27
service2:06
service3:35
service4:07
service5:07
service6:45

Given that the fields are separated by tabs, you should use the -f option to cut instead:

如果文件使用tab鍵隔開就直接使用-f就可以了，-d的默認分隔符號就為tab鍵。

關鍵字：CUT  cchars file