Linux Daily one command--cut

--Sort by file size shows the first 100 rows showing the last five columns

Ll-sh|head-n 100|cut-d '-F 5-

First, the basic grammar
Cut is a selection command that, in the unit of behavior, divides the rows into fields with the specified delimiter and selects the required fields.
1. Syntax format
Cut [option] files
Option common parameters are as follows:

-D: Used to define the delimiter, the default is the TAB key, generally with-F with (if the delimiter is a space, must be two single quotation marks do have a space, is a oh, not support multiple)
-F: The field to be selected, selected according to the field set of-D shard, subscript starting from 1
-S: Indicates that no delimiter-free lines are used to remove information such as comments or headings
-C: Split in characters, you can select a specified character
-B: Split in bytes, you can select a specified byte, which ignores multibyte character boundaries (for example, kanji) unless the-n parameter is also specified
-N: To ungroup multibyte characters, only with the-B parameter, that is, if the last byte of the character falls within the range specified by the-B argument list, the character is selected, otherwise the character is excluded.
It is not difficult to see that the above parameters,-F,-C, and-B are used to represent the extraction of the specified range of data, the range is represented by the following:

N: Fetch only the nth item
N: from Nth to the end of the line
N-m: From Nth to M (including m)
-M: From the first item to the M item (including m items)
-: All items from the start of the first entry to the end
Second, the application example
1. Basic usage
Use the-D and-f combinations to select fields, which are illustrated in path as an example:

Copy Code code example: #echo $PATH
/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/home/changquan.scq/bin

(1) Select a 2nd path:

Copy Code code example: #echo $PATH | Cut-d:-f2
/usr/local/bin

(2) Select all paths after the 2nd start:

Copy Code code example: #echo $PATH | Cut-d:-f2-
/usr/local/bin:/bin:/usr/bin:/home/changquan.scq/bin

(3) Select the 2nd to 4th path, including the 4th path:

Copy Code code example: #echo $PATH | Cut-d:-f2-4
/usr/local/bin:/bin:/usr/bin

(4) Select a path from 1th to 4th, including the 4th path:

Copy Code code example: #echo $PATH | Cut-d:-f-4
/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin

(5) Select all paths from the 1th to the last path:

Copy Code code example: #echo $PATH | Cut-d:-f-
/usr/kerberos/bin:/usr/local/bin:/bin:/usr/bin:/home/changquan.scq/bin
(6) Select the 1th path and the 3rd path:

Copy Code code example: #echo $PATH | Cut-d:-f1,3
/usr/kerberos/bin:/bin

(7) Select the 1th to 3rd path and the 5th path:

Copy Code code example: #echo $PATH | Cut-d:-f1-3,5
/usr/kerberos/bin:/usr/local/bin:/bin:/home/changquan.scq/bin
2. Character positioning
This is illustrated by the WHO example:

Copy Code code example: #who
CHANGQUAN.SCQ pts/02014-05-13 16:21 (10.62.50.159)
CHANGQUAN.SCQ pts/12014-05-13 17:53 (10.62.50.159)
CHANGQUAN.SCQ pts/22014-05-13 18:09 (10.62.50.159)
CHANGQUAN.SCQ pts/32014-05-13 18:34 (10.62.50.159)
CHANGQUAN.SCQ pts/42014-05-13 18:37 (10.62.50.159)
CHANGQUAN.SCQ pts/52014-05-13 19:08 (10.62.50.159)

(1) Extract the 3rd byte of each line:

Copy Code code example: #who | Cut-c3
A
A
A
A
A

(2) Extract the 1th byte from the beginning to the 3rd byte, including the 3rd byte:

Copy Code code example: #who | Cut-c-3
Cha
Cha
Cha
Cha
Cha

(3) Extracts all bytes starting from the 3rd byte to the end, including the 3rd byte:

Copy Code code example: #who | cut-c3-
ANGQUAN.SCQ pts/02014-05-13 16:21 (10.62.50.159)
ANGQUAN.SCQ pts/12014-05-13 17:53 (10.62.50.159)
ANGQUAN.SCQ pts/22014-05-13 18:09 (10.62.50.159)
ANGQUAN.SCQ pts/32014-05-13 18:34 (10.62.50.159)
ANGQUAN.SCQ pts/42014-05-13 18:37 (10.62.50.159)
ANGQUAN.SCQ pts/52014-05-13 19:08 (10.62.50.159)

(4) Extract the entire row, and the 3rd byte does not overlap:

Copy Code code example: #who | cut-c-3,3-
CHANGQUAN.SCQ pts/02014-05-13 16:21 (10.62.50.159)
CHANGQUAN.SCQ pts/12014-05-13 17:53 (10.62.50.159)
CHANGQUAN.SCQ pts/22014-05-13 18:09 (10.62.50.159)
CHANGQUAN.SCQ pts/32014-05-13 18:34 (10.62.50.159)
CHANGQUAN.SCQ pts/42014-05-13 18:37 (10.62.50.159)
CHANGQUAN.SCQ pts/52014-05-13 19:08 (10.62.50.159)

(5) Extract the 3rd to 5th and 8th bytes of each line:

Copy Code code example: #who | cut-c3-5,8
Anga
Anga
Anga
Anga
Anga

3, byte positioning
The Who is still the example of:
Extracts the 3rd to 5th and 8th bytes of each row:

Copy Code code example: #who | cut-b3-5,8
Anga
Anga
Anga
Anga
Anga

I look at the B and c no difference, in fact, the two in single-byte characters (letters) are basically the same, and in multibyte characters (Chinese characters) there is a great difference, here is the Chinese character extraction as an example of:

Copy Code code example: #vi test.txt
Monday
Tuesday
Wednesday
#cut-b3 Test.txt
?
?
?
#cut-c3 Test.txt
One
Two
Three

It is not difficult to see from the above example that the-C output is normal in characters, and-B output garbled in bytes.
Of course,-B is not a drug-free when encountering multibyte characters, and a parameter-n can be used to tell the cut not to disassemble multibyte characters:

Copy Code code example: #cut-NB 2

#cut-NB
Star
Star
Star

Linux Daily one command--cut