AWK

From Network Security Wiki
Jump to navigation Jump to search


Basics

Source: geeksforgeeks.org

  • Awk is a scripting language used for manipulating data and generating reports.
  • Field variables — $1, $2, $3,
  • $0 is the entire line.
  • Usage:
cat stats_collection.log | grep svmem | awk '{print $1 " " $2," - ",$7}'

Built In Variables

  • NR: current count of the number of lines.
awk '{print NR,$0}' employee.txt 
  • NF: count of the number of fields within the current input record.
awk '{print $1,$NF}' employee.txt 
awk 'NR==3, NR==6 {print NR,$0}' employee.txt       =>   Display Line From 3 to 6
awk 'END { print NR }' employee.txt                 =>   Count the lines in a file
  • FS: Field separator character.
The default is “white space”, meaning space and tab characters. 
FS can be reassigned to another character (typically in BEGIN) to change the field separator.

Examples

  • To find/check for any string in any column:
awk '{ if($3 == "B6") print $0;}' employee.txt
  • Print lines with more than 10 characters:
awk 'length($0) > 10' employee.txt



References





blog comments powered by Disqus