Title: Using the cut command
Action: Cut command file in units, in bytes, characters specified field separator cut rows, required to extract segments of the content.
First, use :
cut [-bn] [file] 或cut -c [file] 或cut -[df] [file]
command and writes the cut line cut from each byte, character, and these files byte field, and character fields to standard output. If you do not specify a File Second, the parameters, cut command reads standard input. You must specify -b, -c or one of the -f flag.
Second, the parameters:
-b (byte): divided in byte unit. These byte positions will ignore multi-byte character boundary, unless the -n flag is also specified
-c (character): the character is divided into units
-d (delimiter): Custom delimiter, default tab
-f (fileds): used with -d, which specifies the display area
-n: Cancel split multi-byte characters. Only used with the -b flag. If the last-byte character falls indicated by the List parameter -b flags change
Within the scope of the line, the character will be written out; otherwise, the character will be excluded.
Third, examples
1. extracts the character in the specified range
(1) cut -c n1-n2 filename (n1 and n2 are taken to specify the range of characters, n1 is the starting position, n2 is the OFF position specified filename file name)
filename:number.txt
10 10
20 20
14 14
11 11
Command: cut -c 1-2 number.txt
Output:
10
20
14
11
Description: The contents of the documents, then characters, kanji character length in Unix in UTF-8 encoding 3 is occupied, it is necessary to extend the length of a character corresponding to 3.
(2) For example: If the file weekday reads:
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
So if you want to extract the first kanji "star" of the command is: cut -c 1-3 tmp
2. Extract byte within the specified range
(1) number.txt extracts two bytes of content 1-2
Command: cut -b 1-2 number
Output:
10
20
14
11
3. The specified field separator to extract the contents of a field (-d -f and used in conjunction with)
(1) is in accordance with the contents of $ PATH: dividing, if you want extracted by: dividing the contents of the second field
Command: echo $ PATH | cut -d ':' -f 2
Output: / usr / local / sbin