Linux Three Musketeers awk, SED, grep

Linux Three Musketeers awk, SED, grep

1, awk is mainly used to do the breakdown, matching, calculation work
2, SED is mainly used to do the replacement (stream processing)
3, grep is mainly used to filter out the required text

awk (the default delimiter is a space) awk-f ":" '/bonzi/{if (nr==2) print $} ' (General mode)

-F Set delimiter, you can set multiple delimiters-F "[:!] +"

NR denotes line number

$NF indicates a trailing line

NF number of fields in the current record

Built-in functions

Gsub (R,s)	Use s instead of R for the entire $
Gsub (r,s,t)	Replace R with S in the whole t
Index (S,T)	Returns the first position of the string T in S
Length (s)	return s length
Match (S,R)	Tests if s contains a string matching R
Split (S,A,FS)	Dividing s into sequence a on FS
Sprint (FMT,EXP)	Returns the EXP formatted by FMT
Sub (r,s)	Replace s with the longest substring in the leftmost string
SUBSTR (S,P)	Returns the suffix part of the string s starting from P
SUBSTR (S,p,n)	Returns the suffix part of the string s from p starting at length n

Sed (stream edit) sed-n ' 2s# Original # change #g ' file

-N cancels the default output

-I modify Content

-E allows multiple edits

-R Extended Regular

Sed-n '/bonzi/s# Original # change #gp ' file

Sed-i ' 2,5s# Original # change #g ' file

Examples of latter references:

[Email protected] test]# ifconfig eth1|sed-nr ' 2s#.*addr: (. *) BC.*$#\1#GP '
192.168.1.8

grep (filter text)

-V Exclusion

-I is case insensitive

-o outputs only matching content

-A print matches to the following line,-a 3 prints after three lines

-B Prints the preceding line that matches to,-B 4 prints the first 4 lines

-C print the line that matches to the context, and-C 5 prints the top and bottom 5 lines

Linux Three Musketeers awk, SED, grep