Comparing two timestamps

Shell Programming and Scripting
1

Hi all!!,

I'm using Ksh and working on Linux.

I want to compare two timestamps, timestamp1 and timestamp2.
Until, timestamp1 is lesser than timestamp2, i want to do something, lets say print something.

The code i have written is:

 
a=`date +%H:%M:%S`
b=`date +%H:%M:%S -d" 1 minute"`
echo $a
echo $b
while [ $a -le $b ];
do
echo "You have time"
a=`date +%H:%M:%S`
done

I tried executing this, but the output i get is :

 
03:55:57
03:56:57
date.sh: line 5: [: 03:55:57: integer expression expected

The problem is with the while loop condition.

Please help me on that.

Any help appreciated.
Thanks in advance!!

2

Remove the colons from the dates. They're not numeric, and you're doing a numeric comparison.

Alternatively:

  while [ ${a//:} -le ${b//:} ]; do
    ..
  fi

  ..