Analysis of AWK usage

Analysis of AWK usage
Cut command limitations

Df-h | cut-d ""-f 5/etc/passwd

The cut command cannot correctly intercept the content with spaces as the separator.

AWK format

Awk 'condition 1 {Action 1} condition 2 {Action 2 }... 'Filename'

Condition (Pattern) [relational expressions are generally used as conditions]:

X> 10 determine whether variable x is greater than 10

X> = 10 is greater than or equal

X <= 10 is less than or equal

Action ):

Formatted output: printf, print [\ n will be automatically added]

Process control statement: if/

Percentage of truncated/partitioned data

Df-h | grep sda2 | awk '{print $5}' | cut-d %-f1

BEGIN

Awk 'in in {printf "This is a test Script \ n"} {print $2 "\ t" $5} 'student.txt # first run the command followed by BEGIN

Awk 'in in {FS = ":"} {print $1 "\ t" $3} '/etc/passwd # display the specified separator

Awk-F: '{print $1 "\ t" $3}'/etc/passwd # Same as before

END

Cat/etc/passwd | grep/bin/bash | awk-F: 'End {print "The END... "} {print $1" \ t "$3} '# print the END Content Before the command ends.

Relational operators

Cat student.txt | grep-v NAME | awk '$3> = 80 {print $2 }'

Awk '$3> = 80 {print $2}' student.txt | grep-v NAME # An error may occur.