simple histogram in awk

funcs.awk

nkodner@hadoop4 tmp$ cat coins.txt 
gold     1    1986  USA                 American Eagle
gold     1    1908  Austria-Hungary     Franz Josef 100 Korona
silver  10    1981  USA                 ingot
gold     1    1984  Switzerland         ingot
gold     1    1979  RSA                 Krugerrand
gold     0.5  1981  RSA                 Krugerrand
gold     0.1  1986  PRC                 Panda
silver   1    1986  USA                 Liberty dollar
gold     0.25 1986  USA                 Liberty 5-dollar piece
silver   0.5  1986  USA                 Liberty 50-cent piece
silver   1    1987  USA                 Constitution dollar
gold     0.25 1987  USA                 Constitution 5-dollar piece
gold     1    1988  Canada              Maple Leaf

nkodner@hadoop4 tmp$ awk -f funcs.awk coins.txt 
Number of records per country:
  Austria-Hungary 1   *
  USA             7   *******
  Canada          1   *
  Switzerland     1   *
  PRC             1   *
  RSA             2   **


nkodner@hadoop4 tmp$ cat funcs.awk 
function hist(n)
{
	ret = ""
	for(i=1; i<=n; i++)
	{
		ret = ret "*"
	}
	return ret
}

{ countries[$4]+=1
} END {
 print "Number of records per country:";
 for (x in countries) printf "  %-15s %-3d %s\n", x, countries[x],hist(countries[x])
}