Linux cut Command

Linux cut command displays each line from the beginning date num1 to num2 text.

cut  [-bn] [file]
cut [-c] [file]
cut [-df] [file]

Instructions for use:

cut from each command line cut bytes, characters, and fields file and writes these bytes, characters, or fields to standard output.

If you do not specify a File parameter, cut command reads standard input. You must specify the -b, -c, or -f flag.

parameter:

-b: divided in units of bytes. These byte positions ignore multibyte character boundaries unless the -n flag is also specified.
-c: the characters split units.
-d: custom delimiter, the default tabs.
-f: used with -d, which specifies the display area.
-n: Cancel split multi-byte characters. Only the -b flag. If the last-byte characters within a range of falls by the List parameter -b flag indication of the character will be written out; otherwise, the character will be excluded

When you execute the who command, output similar to the following topics:

$ who
rocrocket :0           2009-01-08 11:07
rocrocket pts/0        2009-01-08 11:23 (:0.0)
rocrocket pts/1        2009-01-08 14:15 (:0.0)

If we want to extract the first three bytes of each line, so:

$ who|cut -b 3
c
c

Linux Tutorial