Implement tail with awk

Question

Alright so here i am struggling with this awk code wich should emulate the tail command

num=$1;
{
    vect[NR]=$0;

}
END{
    for(i=NR-num;i<=NR;i++)
            


        

Answer 1

for(i=NR-num;i<=NR;i++)
    print vect[$i]

$ indicates a positional parameter. Use just plain i:

for(i=NR-num;i<=NR;i++)
    print vect[i]

The full code that worked for me is:

#!/usr/bin/awk -f
BEGIN{
        num=ARGV[1];
        # Make that arg empty so awk doesn't interpret it as a file name.
        ARGV[1] = "";
}
{
        vect[NR]=$0;
}
END{
        for(i=NR-num;i<=NR;i++)
                print vect[i]
}

You should probably add some code to the END to handle the case when NR < num.