[AWK intro] #linux #cmd

awkEndStatement.sh

awk '{a+=$(NF-2)}END{print "Total:", a}' logs.txt

# Output:
# Total: 504

awkIfStatement.sh

awk '{if ($(NF-2) == "200") {print $0}}' logs.txt

# Output:
# 07.46.199.184 [28/Sep/2010:04:08:20] "GET /robots.txt HTTP/1.1" 200 0 "msnbot"

awkPrintColumFromEnd.sh

awk '{print $1, $(NF-2) }' logs.txt

# Output:
# 07.46.199.184 200
# 123.125.71.19 304

awkPrintColumn.sh

awk '{print $1}' logs.txt


# Output:
# 07.46.199.184
# 123.125.71.19

awkPrintWithRowNumber.sh

# Another cool variable is NR, which is the row number being currently processed.
awk '{print NR ") " $1 " -> " $(NF-2)}' logs.txt

# Output:
# 1) 07.46.199.184 -> 200
# 2) 123.125.71.19 -> 304

awkSeperator.sh

awk '{print $2}' logs.txt  | awk 'BEGIN{FS=":"}{print $1}'

# Output:
# [28/Sep/2010
# [28/Sep/2010

awkSumExpression.sh

awk '{a+=$(NF-2); print "Total so far:", a}' logs.txt

# Output:
# Total so far: 200
# Total so far: 504

awkWithPipe.sh

awk '{print $2}' logs.txt  | awk 'BEGIN{FS=":"}{print $1}' | sed 's/\[//'

# Output:
# 28/Sep/2010
# 28/Sep/2010

logs.txt

07.46.199.184 [28/Sep/2010:04:08:20] "GET /robots.txt HTTP/1.1" 200 0 "msnbot"
123.125.71.19 [28/Sep/2010:04:20:11] "GET / HTTP/1.1" 304 -  "Baiduspider"

# Reference
https://web.archive.org/web/20150906053501/http://gregable.com/2010/09/why-you-should-know-just-little-awk.html