Unable to compare properly with if condition

Question

I have written very simple logic below, but it is always complaining with my if condition.

Here is my code:

#!/bin/sh

UBUNTU_VERSION=`lsb_release -r |  awk '{ print $2}'`
echo "UBUNTU_VERSION - $UBUNTU_VERSION"

if [[ "$UBUNTU_VERSION" -eq "14.04" ]];
then
        echo "Ubuntu 14.04"
else
        echo "Not Ubuntu 14.04"
fi

I get the error as :

./test.sh: 6: ./1.sh: [[: not found

If I change my code to:

if [ "$UBUNTU_VERSION" -eq "14.04" ];

or

if [ $UBUNTU_VERSION -eq "14.04" ];

I get error as :

./test.sh: 6: [: Illegal number: 14.04

I have already referred to this link to correct my code, but I am not able to fix this:

bash : Illegal number

Use the '=' comparator. -eq is reserved for integer comparations. — pah, Jun 22 '16 at 07:11

score 4 · Accepted Answer · answered Jun 22 '16 at 07:11

Use #!/bin/bash shebang at top for using bash syntax
eq is for integer comparison only, use = or ==
Use $(...) for command substitution instead of old fashioned and buggy reverse ticks

Modified Code:

#!/bin/bash

UBUNTU_VERSION=$(lsb_release -r |  awk '{ print $2}')
echo "UBUNTU_VERSION - $UBUNTU_VERSION"

if [[ $UBUNTU_VERSION == "14.04" ]];
then
        echo "Ubuntu 14.04"
else
        echo "Not Ubuntu 14.04"
fi

score 1 · Answer 2 · answered Jun 22 '16 at 07:11

1

[[ is a bash-ism i.e. it is a bash keyword.

As you are interpreting the script as sh, which presumable is not bash and does not support [[ (dash?), hence the error.

answered Jun 22 '16 at 07:11

heemayl

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score 1 · Answer 3 · answered Jun 22 '16 at 07:12

Note: -eq ,-ne ,-gt ,-lt are used to compare integers. For string it won't work. You need to use == , !=

  UBUNTU_VERSION=`lsb_release -r |  awk '{ print $2}'`
   echo "UBUNTU_VERSION - $UBUNTU_VERSION"

if [ "$UBUNTU_VERSION" == "14.04" ];
then
        echo "Ubuntu 14.04"
else
        echo "Not Ubuntu 14.04"
fi

Unable to compare properly with if condition

3 Answers3