Problem with date in conjunction with cut?

Shell Programming and Scripting
1

I got rather bored so i decided to create a script that creates a countdown, and shows hours:minutes:seconds till that time.
It works fine until the seconds of the actual time reaches 8, then it tries to use it to work out the difference as in "SECONDDIFF=$[SECOND-ALARMSECOND]"
Here's my code where I get the problem :

ALARMHOUR=`echo "$ALARMTIME" | cut -d : -f 1 `
ALARMMINUTE=`echo "$ALARMTIME" | cut -d : -f 2 `
ALARMSECOND=`echo "$ALARMTIME" | cut -d : -f 3 `
...

TIME=`date "+%H:%M:%S"`

HOUR=`echo "$TIME" | cut -d : -f 1 `
MINUTE=`echo "$TIME" | cut -d : -f 2 `
SECOND=`echo "$TIME" | cut -d : -f 3 `

SECONDDIFF=$[SECOND-ALARMSECOND]
SECONDDIFF=$[60-SECONDDIFF]

The line i get the error at is SECONDDIFF=$[SECOND-ALARMSECOND] and
The error i'm getting is :
/bin/TermTime (unstable): line 35: 08: value too great for base (error token is "08")
I simply cannot even guess how to fix this, i simply have no idea, Help me please someone?

2

What shell are you using?

There's several ways better than running cut 3 times to process one line.

A way that'll work in all shells:

VAR="12:34:56"

OLDIFS="$IFS"
IFS=":";   set -- $VAR;   IFS="$OLDIFS"
HH=$1
MM=$2
SS=$3

This will overwrite your $1,$2,$3 parameters.

Other ways may be available depending what your shell is.

1 Like
3

I'm using BASH... On a mac running lion if that helps

4

It does.

Try X=$((Y-Z)) instead of X=$[Y-Z].

BASH can also do this:

read A B C <<<$(date +"%H %M %S")

Hundreds of times faster than running three external utilities to process one line.

5

or:

#!/bin/ksh
eval "$( date '+ h=%H =%H m=%M s=%S' )"
echo $h $m $s
6

Thank you for the help speeding up the execution, however I only posted for the problem i was getting... Any idea what it is and how to sort it out?

7

Check my last post. I answer your question directly and tell you how to fix it.

8

Oh ok thank you, I didn't see that bit... somehow.. Thank you :slight_smile:

---------- Post updated at 06:41 PM ---------- Previous update was at 06:36 PM ----------

So @Corona, Whats the difference between '[' and '(('?

Just tested it, it hasn't fixed the problem... And i thought it had

9

$(( is BASH arithmetic syntax, $[ isn't. I don't regognize this $[ syntax at all, for any language I know.

If it doesn't work, please post what you tried and what happened.

10

This is the body of the code i use (been updated with the '((' that you recomended)

ALARMHOUR=`echo "$ALARMTIME" | cut -d : -f 1 `
ALARMMINUTE=`echo "$ALARMTIME" | cut -d : -f 2 `
ALARMSECOND=`echo "$ALARMTIME" | cut -d : -f 3 `

for (( ;; )) do
  clear
  TIME=`date "+%H:%M:%S"`

read HOUR MINUTE SECOND <<<$(date +"%H %M %S")

  SECONDDIFF=$((SECOND-ALARMSECOND))
  SECONDDIFF=$((60-SECONDDIFF))

  if [ $SECONDDIFF -lt 10 ]; then
    SECONDDIFF="0$SECONDDIFF"
  fi

  MINUTEDIFF=$(($MINUTE-$ALARMMINUTE))
  MINUTEDIFF=$((59-MINUTEDIFF))

  if [ $MINUTEDIFF -lt 10 ]; then
    MINUTEDIFF ="0$MINUTEDIFF"
  fi

  HOURDIFF=$(($HOUR-$ALARMHOUR))
  if [ $HOURDIFF -lt 0 ]; then
    HOURDIFF=$((HOURDIFF-HOURDIFF-HOURDIFF))
  elif [ $HOURDIFF -gt 0 ]; then
    HOURDIFF=$((24-HOURDIFF))
  fi

  if [ $HOURDIFF -lt 10 ]; then
    HOURDIFF="0$HOURDIFF"
  fi

  echo "Current time : $HOUR:$MINUTE:$SECOND"
  echo ""
  echo "  Alarm time : $ALARMTIME"
  echo ""
  echo "  Difference : $HOURDIFF:$MINUTEDIFF:$SECONDDIFF"
  ...
  sleep 1
done

It cycles through that, updating every second, but when SECONDS reaches 08, it exits with the following error :
/bin/TermTime (unstable): line 33: 08: value too great for base (error token is "08")

I have tried setting the SECONDS variable in the form :

if [ $SECONDS = 8 ]; then
SECONDS=8
fi

Didn't expect it to work and it didn't, but i thought i would try it
The strange thing is that i don't think it does this with MINUTES or HOURS, just SECONDS...

What do you suggest?

11

Ah -- BASH assumes numbers beginning with 0 are octal.

Do

STRING="${STRING#0}"

to strip off the leading zero when present. Do this for hours, minutes, and seconds.

Also:

IFS=":" read ALARMHOUR ALARMMINUTE ALARMSECOND <<<"$ALARMTIME"

will be hundreds of times faster than running cut three times to process one string...

---------- Post updated at 01:34 PM ---------- Previous update was at 01:30 PM ----------

Also: Your TIME variable doesn't appear to do anything anymore.

1 Like
12

Thank you, just waiting for it to come round and...It works. Thank you so much, this has been bugging me since last night sometime...
My final question is : How can i stop it from saying "Current time : 19:44:1"
and make it say "Current time : 19:44:01" without screwing it all up?
Never mind, Thank you so much Corona, you've been a great help

13 
printf "Current time:  %02d:%02d:%02d\n" $HH $MM $SS