0
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 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.

1
  • 5
    One cannot explain this abomination of code. From uninitialized variables ($ii used in a test) to inconsistent spelling and capitalization of the months, to an undocumented and clearly uncommon input requirement.
    – KevinO
    Jun 16 '17 at 15:27
1

$1 is the first positional parameter, i.e. argument to the function. awk -F- sets awks field separator to a dash, and print $2 prints the second field. So from aa-bb-cc, you'd get bb.

Presumably the function expects to be called as getDateFormat something-2017-06 which looks odd, but the year is picked from the second dash-separated field.

$ii would refer to a variable, but it's not set before the test if [ $mm -eq $ii ]; so the test sees [ 123 -eq ] (with 123 probably some number picked from $1). That causes an error since the operator -eq is missing the other operand.

8
  • ii is undefined on the first iteration, but that's semantically zero; on subsequent iterations, it gets incremented. I don't think the logic is entirely correct, but with a few fixes, the loop would convert -- horribly clumsily -- from a month name to a month number. (Notice also how the month names use erratic capitalization and abbreviation conventions, and how July is incorrectly listed before June.)
    – tripleee
    Jun 16 '17 at 15:43
  • I guess with ii=1 instead of i=1 it would superficially work for many month names.
    – tripleee
    Jun 16 '17 at 15:47
  • mm is set before the loop, apparently to the month name.
    – tripleee
    Jun 16 '17 at 15:47
  • @tripleee, without changing from i=1 to ii=1, I get an error in bash on the first loop, so I think it needs to be set prior to the first loop iteration as you subsequently noted.
    – KevinO
    Jun 16 '17 at 15:56
  • @tripleee, sorry, my bad on the mm. But since $ii is unquoted, it resolves to nothing, so that still doesn't work... And even when quoted, I think the empty string would give an error from -eq.
    – ilkkachu
    Jun 16 '17 at 16:16

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