Linux Shell Command (2)-CAT/CUT/paste/SED/TR/grep/sort/uniq

Who

• All users currently logged in to the system

Cat

• Examine the contents of a file

WC-l

WC-W

WC-C

• Get a count of the total number of lines, words, and characters of information contained in a file

 

Cut

Cut-cchars File

 
$ Who
 

 
Root console Feb 24 08:54
 

 
Steve tty02 Feb 24 :55
 

 
George tty08 Feb 24
 

 
Dawn tty10 Feb 24 :55
 

 
$ Who | cut-c1-8 extract the first 8 characters
 

 
Root
 

 
Steve
 

 
George
 

 
Dawn
 

 
$
 

 
$ Who | cut-c1-8, 18-
 

 
Root Feb 24 :54
 

 
Steve Feb 24 :55
 

 
George Feb 24
 

 
Dawn Feb 24 :55
 

 
$
 

-DAnd-FOptions

Divide parameters into multiple fields using the-D delimiter.-F specifies which fields

If no delimiters are specified, tab is used as the delimiters.

 
$ CAT/etc/passwd
 

 
Root: *: 0: 0: The Super User: // usr/bin/KSh
 

 
Cron: *: 1: 1: Cron DaemonForPeriodic tasks :/:
 

 
Bin: *: 3: 3: The owner of system files :/:
 

Uucp: *: 5: 5:/usr/spool/uucp:/usr/lib/uucp/uucico
 

 
ASG: *: 6: 6: The owner of assignable devices :/:
 

 
STEVE: *: 203: 100:/users/STEVE:/usr/bin/KSh
 

 
Other: *: 4: 4: needed by secure program :/:
 

 
$ Cut-D:-F1/etc/passwd extract Field 1
 

 
Root
 

 
Cron
 

 
Bin
 

 
Uucp
 

ASG
 

 
Steve
 

 
Other
 

 
$ Cut-D:-F1, 6/etc/passwd extract fields 1 and 6
 

 
Root :/
 

 
Cron :/
 

 
Bin :/
 

 
Uucp:/usr/spool/uucp
 

 
ASG :/
 

 
STEVE:/users/Steve
 

Other :/
 

 
$
 

 

Grep

Grep pattern filesSearch mode string

*,? Can be applied to mode strings and file names

Example of a regular expression:

Grep '[A-Z]' list	Lines fromListContaining a capital letter
Grep '[0-9] 'data	Lines fromDataContaining a number
Grep '[A-Z]... [0-9] 'list	Lines fromListContaining five-character patterns that start with a capital letter and end with a digit
Grep '\. PIC $ 'filelist	Lines fromFilelistThat end in. PIC

Grep-ICase Insensitive

Grep-VFind the row of the unmatched pattern string

Grep-lOnly list files containing mode strings

Grep-nAn additional matched row number is provided.

Sort

Sort

Sort-u remove duplicate items

Sort-r reverse sorting

Sort-O redirection to the file sort names-O sorted_names is equivalent to sort names-o> sorted_names

Sort-N arithmetic sorting, not character sorting

Sort + 1n skips 1st fields and performs arithmetic sorting

Sort-T specifies the delimiter to separate fields. Generally, sort + 1n is separated by space or tab by default.