How can find Null value in If condition

koti_rama · #1 (**permalink**) 07-17-2007

Hi,
i wrote If Conditions in my script, it's returns null and some values.
but i am unable to find when Null value getting. bec we need modification according null vales.
pls help me on this.

vino · #2 (**permalink**) 07-17-2007

NULL strings would translate to a string of length zero.

You could do this to check for the NULL'ness of a string.

Code:

if [ ! -n "$VARIABLE" ] ; then
  echo "VARIABLE is empty"
fi ;

or

Code:

if [ -z "$VARIABLE" ] ; then
  echo "VARIABLE is empty"
fi ;

See man test to see the description of the flags -n and -z

srikanthus2002 · #3 (**permalink**) 07-17-2007

Code:

if [ "x $value" == "x """ ]
#if [ ! -n "$value" ]
then
        echo "empty"
else
        echo "Not empty"
fi

try it out..

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