UNIX for Dummies Questions & Answers

A|B|C|D
A|F|C|E
A|B|I|C
A|T|I|B

1|3|2|4

gawk 'BEGIN{FS=OFS="|"}{for(i=1; i<=NF; i++) a[$i]++} END {for (b in a) print b}' input

gawk '

BEGIN {
  FS=OFS="|"
}

{
  for (i = 1; i <= NF; i++)
    a[i, $i]++;
}

END {
  for (i = 1; i <= NF; i++)
  {
     $i = 0;
     for (j in a)
     {
         split (j, k, SUBSEP);
         if (i == k[1]) $i++;
     }
  }
  print
}

' input

awk 'BEGIN{FS="|"}
{
 for(i=1;i<=NF;i++)
  c[i,$i]++
 if(NF>max)
  max=NF
}
END{
 for(i in c)
 {
  split(i,b,SUBSEP)
  d[b[1]]++
 }
 for(i=1;i<=max;i++)
  printf "%s|", d[i]
 print ""
}' file