[root@localhost cee]# echo -e "line1\nline2"|awk '{ print }'

line1

line2

[root@localhost cee]# echo -e "line1\nline2"|awk 'BEGIN{ print "START"} { print }'

START

line1

line2

[root@localhost cee]# echo -e "line1\nline2"|awk 'BEGIN{ print "START"} { print } END{ print "END" }'

START

line1

line2

END

[root@localhost cee]# echo | awk '{ var1="v1";var2="v2";var3="v3"; print var1,var2,var3}'

v1 v2 v3

[root@localhost cee]# echo | awk '{ var1="v1";var2="v2";var3="v3"; print var1"-"var2"-"var3}'

v1-v2-v3

[root@localhost cee]# echo -e "line1 f2 f3\nline2 f4 f5\nline3 f6 f7"

line1 f2 f3

line2 f4 f5

line3 f6 f7

[root@localhost cee]# echo -e "line1 f2 f3\nline2 f4 f5\nline3 f6 f7"| awk '{ print "Line no:"NR",No of filelds:"NF, "$0="$0, "$1="$1,"$2="$2,"$3="$3 }'

Line no:1,No of filelds:3 $0=line1 f2 f3 $1=line1 $2=f2 $3=f3

Line no:2,No of filelds:3 $0=line2 f4 f5 $1=line2 $2=f4 $3=f5

Line no:3,No of filelds:3 $0=line3 f6 f7 $1=line3 $2=f6 $3=f7

[root@localhost cee]# echo -e "line1 f2 f3\nline2 f4 f5\nline3 f6 f7" | awk '{ print $3,$2}'

f3 f2

f5 f4

f7 f6

[root@localhost cee]# echo -e "line1 f2 f3\nline2 f4 f5\nline3 f6 f7" | awk '{ print $0}'

line1 f2 f3

line2 f4 f5

line3 f6 f7

[root@localhost cee]# echo -e "line1 f2 f3\nline2 f4 f5\nline3 f6 f7"

line1 f2 f3

line2 f4 f5

line3 f6 f7

echo -e "line1 f2 f3\nline2 f4 f5\nline3 f6 f7" | awk 'END{ print NR }'

3

[root@localhost cee]# seq 5

1

2

3

4

5

[root@localhost cee]# seq 5 | awk 'BEGIN{ sum=0; print "Summation:" } { print $1"+"; sum+=$1 } END{ print "=="; print sum }'

Summation:

1+

2+

3+

4+

5+

==

15