Has some crossover abilities but really shines with displaying or translating column data.

Example usage:

Find something in a file, then display the first two columns:

grep '<something>' somewhere.txt | awk '{print $1, $2}'

Output data in a more formatted way:

awk '{printf "%-10s %s\n", $1, $2}' file.txt

RS = record separator (newline)

FS = field separator (all whitespace)

NR = number of records (current index)

NF = number of fields in current record

OFS = output field separator (default is space but for CSV you could use a ,)

awk 'BEGIN {OFS=","} {print $1, $2}' file.txt

ORS = output record separator (default is newline but could use two newlines or maybe a semicolon, etc)

awk 'BEGIN {ORS="; "} {print $1}' file.txt

ARGV = argument list, 0 is awk itself. Normal.

ARGC = argument count, not including awk itself.

FILENAME = current file being processed

ENVIRON = environmental variables, like php's $_SERVER

awk 'BEGIN {print ENVIRON["HOME"]}'

BEGIN / END = special blocks that process before and after the actual output loop. Allow you to output stats or maybe change the record and field variables.

Examples:

git branch --v | grep "\[gone\]" | grep -v 'ha\/' | awk '{print $1}'| xargs git branch -d