AWK Commands for Linux

1: Field/text processor
2: Default Field-delimiter is white-space.
3: Stores fields (columns) into tokens, which then become accessible during processing
4: Will accept input from: file or STDIN or pipe


Commands:

1: To print each line in its entirety.

# awk '{ print $0 }' test.txt

2: To print column #1 from each line.

# awk '{print $1}' test.txt

3: To print column #2 from each line.

# awk '{print $2}' test.txt

4: To print column #1 then #2.

# awk'{print $2,$1}' test.txt

5: To print all columns where line includes 'Red'.

# awk'/Red/ {print $0}' test.txt

6: To print column #1,#2,#3 where line include 'Red'.

# awk '/Red/ {print $1, "-",$2,"-",$3}' test.txt

7: To print all columns of records containing '2012' in the second column.

# awk '{if ($2 ~ /2012/) print $0}' test.txt

8: To print lines ending in : 2012.

# awk '/2012$/ {print $0}' test.txt

9: Accept a pipe using above point 8 commands.

# grep 2012 /var/log/messages | awk '/2012/ {print $0}'

10: To print columns $3-$6 where column 2 = '9'.

# awk '{if ($2 ~ /9/) print $3,$4,$5,$6}' /var/log/message