getDateFormat() {  year=`echo $1 | awk -F- '{print $2}'`  mm=`echo $1 | awk -F- '{print $3}'`  i=1  for x in January February march april may july jun august September October November December  do    if [ $mm -eq $ii ]; then      month=$x      break    fi    ii=`expr $ii + 1`  done  mday=`echo $1 | awk -F_ '{print $1}' | awk -F- '{print $4}'`  tmp_date=${mday}_${month}_$year}I am beginner in shell scripting. I would like to know What does the above function do?  $ awk '$2 == 1 { print $0 }' cols.txt Where the match occurs, print the entire line. But what this command returns echo $1 | awk -F- '{print $2}'$ii - What is this?i=1;echo $ii It didn't print anything. 
please explain below command
shell script;shell;awk;variable