awk '{sub(/^[ \t]+/, ""); print}' dummy.txt 

awk '{sub(/[ \t]+$/, "");print}'

awk '{gsub(/^[ \t]+|[ \t]+$/,"");print}' dummy.txt

awk '{$1=$1;print}' dummy.txt

awk '{sub(/^/, "     ");print}' dummy.txt

awk '{printf "%79s\n", $0}' dummy.txt*

awk '{l=length();s=int((79-l)/2); printf "%"(s+l)"s\n",$0}' dummy.txt*

awk '{sub(/Lorem/,"foo");print}' dummy.txt

awk '{sub(/Lorem/,"foo");print}' dummy.txt | grep --color=always foo

awk '/Lorem/{gsub(/ipsum/, "foo")};{print}' dummy.txt

awk '!/Lorem/{gsub(/sit/, "foo")};{print}' dummy.txt

awk '{gsub(/Lorem|ipsum|dolor/, "foo"); print}' dummy.txt

awk '{a[i++]=$0} END {for (j=i-1; j>=0;) print a[j--] }' dummy.txt*

awk '/\\$/ {sub(/\\$/,""); getline t; print $0 t; next}; 1' dummy.txt*

awk -F ":" '{ print $1 | "sort" }' /etc/passwd

awk '{print $2, $1}' dummy.txt

awk '{temp = $1; $1 = $2; $2 = temp}' dummy.txt

awk '{ $2 = ""; print }' dummy.txt

awk '{for (i=NF; i>0; i--) printf("%s ",i);printf ("\n")}' dummy.txt

awk 'a !~ $0; {a=$0}'

awk '! a[$0]++'                
awk '!($0 in a) {a[$0];print}'