UNIX入門課程1051_ex8

http://erdos.csie.ncnu.edu.tw/~klim/unix-intro/unix-intro-1051.html

作業八: figure out the average and the max three (awk programming)
跟作業六一樣, 但改用 awk 來寫.
請全用 awk 來寫, 不要混用 sh 或 sed.
請寫成一個 script file, 並設定成可執行.
input 的 data 內可能有 comment.

$ cat k1
10 20 30 #this is a comment
8 7
# this is also a comment
2
$ ./ex8.awk k1
the max three are: 30 20 10
the average is   : 12.83
$

解答:

#!/usr/bin/awk -f
BEGIN {
}
{
  sub(/#.*/ , "")
  if ( $0 != "" ) {
    for (i=1; i<=NF; i++) {
      num[count]=$i
      sum+=$i
      count++
    } #for END
  } #if END
}
 
END {
  asort(num) #sort num[] array
  printf("the max three are: %d %d %d\n",num[count],num[count-1],num[count-2])
  printf("the average is   : %.2f\n",sum/count)
} 

注意：程式中asort函數在GNU awk 3.1才有提供

執行結果: