Linux Awk Command Examples

AWK is a domain-specific language designed for text processing and typically used as a data extraction and reporting tool. Like sed and grep, it is a filter, and is a standard feature of most Unix-like operating systems.

• awk '{print $2, $3}' my.txt
  • Print 2nd & 3rd fields separated by space
• awk '{print $2 ", " $3}' my.txt
  • Print 2nd & 3rd fields separated by comma
• awk '$2 > 100' my.txt
  • Print lines where 2nd field is > 100
• awk '$1 == 100' my.txt
  • Print lines where 1st field equals to 100
• awk '/error/' my.txt
  • Print lines containing the word ‘error’
• awk '{sum=$1+$2; print sum}' my.txt
  • Sum up 1st & 2nd fields of each line
• awk '{print NR, $0}' my.txt
  • Add line number to each line and print it
• awk '{print NF}' my.txt
  • Print the number of fields in each line
• awk '{print $1, $NF}' my.txt
  • Print 1st & last fields
• awk '{s+=$2; c++} END {print s/c}' my.txt
  • Compute average of 2nd field
• awk '$1 > 100 {s+=$2; c++} END {print s/c}' my.txt
  • Average with condition
• awk '{print toupper($2)}' my.txt
  • Print 2nd field in uppercase
• awk '$1 == "ERR" {print $2}' my.log
  • Print 2nd field if 1st field is “ERR”
• awk -F "," '{print $2, $3}' my.csv
  • Use comma “,” as field separator
• awk '{print substr($2,1,3)}' my.txt
  • Extract substring from 2nd field
• awk 'function sq(x) {return x*x} {print sq($2)}' my.txt
  • Define a function
• awk '!seen[$1]++' my.txt
  • Remove duplicate lines based on 1st field
• awk 'length($2) > 3' my.txt
  • Print lines where length of 2nd field > 3
• awk '$1 ~ /ERR/' my.log
  • Print lines where 1st field matches pattern
• awk '$1 !~ /ERR/' my.log
  • Print lines where 1st field doesn’t match pattern
• awk '$1 ~ /^[0-9]+$/' my.log
  • Print lines where 1st field is a numeric value

Ref: Dan Nanni - X