oam/knowledge base/awk.md

awk

1. TL;DR
2. Further readings

TL;DR

# Print only the 3rd column.
awk '{print $3}' sales.txt
cat sales.txt | awk '{print $3}'

# Print the 2nd and 3rd columns, separated with a comma.
awk '{print $2 ", " $3}' sales.txt
cat sales.txt | awk '{print $2 ", " $3}'

# Print the sum of the 2nd and 3rd columns.
awk '{print $2 + $3}' sales.txt

# Print only lines with a length of more than 20 characters.
awk 'length($0) > 20' sales.txt

# Print only lines where the value of the second column is greater than 100.
awk '$2 > 100' sales.txt

# Print only the last column.
echo 'maps.google.com' | awk -F. '{print $NF}'
awk -F '/' '{print $NF}' <<< 'test/with/slashes'

# Make only the first character uppercase.
echo 'something' | awk '{print toupper(substr($0,0,1))tolower(substr($0,2))}'

Further readings

• Print line only if number in third field is greater than X
• Printing the last column of a line in a file
• The essential Bash cheat sheet