Awk Examples

Resources

• See this excellent [https://www.shortcutfoo.com/app/dojos/awk/cheatsheet cheat sheet].

Defining Functions

This example from [https://www.youtube.com/watch?v=jJ02kEETw70 Gary Explains on youtube]

func round(n) {
  n = n + 0.5
  n = int(n)
  return n
}
/^w/ && $2>9000 { print $1,$2/1024,round($2/1024)"K" }

Line numbers and new files

The variable FNR is the current line number in the current file.

awk '/cout/ {print FILENAME ":" FNR ": " $0}' *.cpp

By comparing FNR to 1, we can detect a new file.

awk 'BEGIN {n=0} FNR==1 {n=n+1;print "New File: " FILENAME} END { print n " files" }' *.cpp

Joining some lines but not others

This joins each group of 5 lines using commas:

awk '{if((NR+1)%5 == 0) { print $0; } else { printf "%s, ",$0; }}'