unixshell(2)

cut 用于取域
-c选项
cut -cchars file
cut -c3,5,6 file
cut -c5-10 file
-d选项
分割符
-f选项
取域
cut -ddchar –ffields file
$ cut -d: -f1 /etc/passwd     Extract field 1
$ cut -d: -f1,6 /etc/passwd   Extract fields 1 and 6
sed -n l file
查看文件分割符号

paste
paste和cut相反，是合并文件
paste files
$ cat names
Tony
Emanuel
Lucy
Ralph
Fred
$ cat numbers
[phone]
[phone]
[phone]
[phone]
[phone]
$ paste names  numbers
Tony    [phone]
Emanuel [phone]
Lucy    [phone]
Ralph   [phone]
Fred    [phone]
$ cat address
55-23 Vine Street, Miami
39 University Place, New York
17 E. 25th Street, New York
38 Chauncey St., Bensonhurst
17 E. 25th Street, New York
$ paste names addresses numbers

-d选项
如果不想使用tab作为域分隔符，可以使用-d来指定
-dchars
$ paste -d'+' names addresses numbers
Tony+55-23 Vine Street, Miami+[phone]
Emanuel+39 University Place, New York+[phone]
Lucy+17 E. 25th Street, New York+[phone]
Ralph+38 Chauncey St., Bensonhurst+[phone]
Fred+17 E. 25th Street, New York+[phone]
-s选项
合并来自同一个文件中的行
$ paste -s names        Paste all lines from names
Tony    Emanuel Lucy    Ralph   Fred
$ ls | paste -d' ' -s - Paste ls's output, use space as delimiter

tr
tr from-chars to-chars

$ tr e x < intro
将intro中e转换成x
$ cat /etc/passwd | tr : '    '
转换:为空
$ date | tr ' ' '\12'   
转换空格为换行

tr转换一个范围
$ tr '[a-z]' '[A-Z]' < intro
小写转换成大写
$ tr '[A-Z]' '[a-z]' < intro

-s选项
$ cat lotsaspaces
This       is   an example  of a
file   that contains       a  lot
of   blank spaces.
$ tr –s ' ' ' ' < lotsaspaces
This is an example of a
file that contains a lot
of blank spaces.
挤掉多个空格

-d选项
tr -d from-chars
删除字符