A poor man's NCSA log analyzer written in (G)AWK

ncsa_stats.awk

# My first GAWK script

{
  total_bytes += $10
}

$9 ~ /2[0-9]+/ {
  n_sc_2xx++
}

$9 ~ /3[0-9]+/ {
  n_sc_3xx++
}

$9 ~ /4[0-9]+/ {
  n_sc_4xx++
}

$9 ~ /5[0-9]+/ {
  n_sc_5xx++
}

END {
  printf "%d requests served:\n", NR
  printf "  2XX=%d (%.2f%%)\n  3XX=%d (%.2f%%)\n  4XX=%d (%.2f%%)\n  5XX=%d (%.2f%%)\n",
    n_sc_2xx, (n_sc_2xx/NR) * 100,
    n_sc_3xx, (n_sc_3xx/NR) * 100,
    n_sc_4xx, (n_sc_4xx/NR) * 100,
    n_sc_5xx, (n_sc_5xx/NR) * 100
  printf "%d bytes sent\n", total_bytes
}

Example usage:

 awk -f ./ncsa_stats.awk /var/log/nginx/*-access.log
 1574 requests served:
   2XX=1288 (81.83%)
   3XX=117 (7.43%)
   4XX=152 (9.66%)
   5XX=0 (0.00%)
 28498436 bytes sent