Code:
BEGIN{
i=1
while ( i <= 1000 ){
var="abcde"
j=1
while ( j <= length(var) ){
if ( substr(var,j,1) == "a" ){
printf "%s", "m"
}else if (substr(var,j,1) == "b"){
printf "%s", "n"
}else if(substr(var,j,1) == "c") {
printf "%s", "o"
}else if(substr(var,j,1) == "d") {
printf "%s", "p"
}else if(substr(var,j,1) == "e") {
printf "%s", "q"
}else if(substr(var,j,1) == "f") {
printf "%s", "r"
}else if(substr(var,j,1) == "g") {
printf "%s", "s"
}else if(substr(var,j,1) == "h") {
printf "%s", "t"
}else if(substr(var,j,1) == "i") {
printf "%s", "u"
}else if(substr(var,j,1) == "j") {
printf "%s", "v"
}else if(substr(var,j,1) == "k") {
printf "%s", "w"
}else if(substr(var,j,1) == "l") {
printf "%s", "x"
}else if(substr(var,j,1) == "m") {
printf "%s", "y"
}else if(substr(var,j,1) == "n") {
printf "%s", "z"
}else if(substr(var,j,1) == "o") {
printf "%s", "a"
}else if(substr(var,j,1) == "p") {
printf "%s", "b"
}else if(substr(var,j,1) == "q") {
printf "%s", "c"
}else if(substr(var,j,1) == "r") {
printf "%s", "d"
}else if(substr(var,j,1) == "s") {
printf "%s", "e"
}else if( substr(var,j,1) == "t") {
printf "%s", "f"
}else if(substr(var,j,1) == "u") {
printf "%s", "g"
}else if(substr(var,j,1) == "v") {
printf "%s", "h"
}else if(substr(var,j,1) == "w") {
printf "%s", "i"
}else if(substr(var,j,1) == "x") {
printf "%s", "j"
}else if(substr(var,j,1) == "y") {
printf "%s", "k"
}else if(substr(var,j,1) == "z") {
printf "%s", "l"
}
j++
}
print
i++
}
}