Strange Number comparison issue

shihabvk · #1 (**permalink**) 04-09-2007

Hi,
I am comparing two numbers, but it gives strange results:
My Code:
if [ ${STARTTIME} -gt ${DATE_TIME} ]
then
echo "True"
else
echo "False"
fi

This code gives False for the follwoing comparison
[ 20040109195224 -gt 20070409200951 ]

where as True for the following:
[ 20050109195224 -gt 20070409201317 ]

Any reason for this? Both Should have given False...

I am using ksh shell on HP UX

Please help me
Shihab

reborg · #2 (**permalink**) 04-09-2007

The numbers are too large for a -gt or -lt type comparison.

Try it with a numerical comparison:

Code:

if (( STARTTIME > DATE_TIME )) ; then
...
fi

or

Code:

if (( $STARTTIME > $DATE_TIME )) ; then
...
fi

*note in numerical comparison the "$" on the variables can be either ommitted or used

shihabvk · #3 (**permalink**) 04-09-2007

Sorry it is not working :-(

reborg · #4 (**permalink**) 04-09-2007

Quote:

Originally Posted by shihabvk

Sorry it is not working :-(

**shrug** It works fine for me, but since you gave no indication of any behaviour or error there is noting I can do.

matrixmadhan · #5 (**permalink**) 04-09-2007

Quote:

Originally Posted by reborg

**shrug** It works fine for me, but since you gave no indication of any behaviour or error there is noting I can do.

Yes,

As pointed, it would work,

here is a sample that I tried in zsh

Code:

if [ 20040109195224 -lt 20070409200951 ]
then
echo "yes"
else
echo "no"
fi
yes

Should work in ksh too !

shihabvk · #6 (**permalink**) 04-09-2007

See My code :
#!/bin/ksh
STARTTIME=20050109195224
DATE_TIME=20070409201317
if (( STARTTIME > DATE_TIME )) ; then
echo "No"
else
echo "Yes"
fi

STARTTIME=20060109195224
DATE_TIME=20070409201317
if (( STARTTIME > DATE_TIME )) ; then
echo "No"
else
echo "Yes"
fi

Gives No for first if and Yes for the second one

As I mentioned using KSH on HP-UX

matrixmadhan · #7 (**permalink**) 04-09-2007

Code:

perl -e 'if ( 20040109195224 < 20070409200951 ) { print "yes\n" }'

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