multi-pass

Npass.awk

# Note! this only works if you pass the input as a file
# so that it can be read by wc.

BEGIN{pass=1; num_passes=4}

NR==1 {
    ( "cat " FILENAME " | wc -l" ) | getline NL
}

# ...enter custom code blocks here...
{print pass,$0}

# Must be the last block
FNR==NL{
    while ( ++pass <= num_passes ) {
        ARGC++
        ARGV[ARGIND+1] = FILENAME
        nextfile
    } 
}