bash string-operator problem

[john doe]

On 2/21/2019 5:18 PM, Lee wrote:
> On 2/21/19, Rockefeller, Harry  wrote:
>> CYGWIN_NT-6.1 HARRYR-PC 3.0.0(0.336/5/3) 2019-02-16 13:21 x86_64 Cygwin
>> GNU bash, version 4.4.12(3)-release (x86_64-unknown-cygwin)
>>
>> #!/bin/bash
>> A="A"
>> B="A"
>> if [ $A!=$B ]; then          <----- needs spaces around the !=
>>     echo -e "not identical"
>> fi
>> if [ $A==$B ]; then         <------ needs spaces around the ==
>>     echo -e "identical"
>> fi
>> exit 0
>>
>> Running this script gives
>> not identical
>> identical
>>
>> Both tests are true.
>
> because you're testing "A==B"
> you need to give 3 parameters  "A"  "=="  "B"
>
> $ cat x
> #!/bin/bash
> A="A"
> B="A"
> if [ $A != $B ]; then
>     echo  "not identical"
> fi
> if [ $A == $B ]; then
>     echo  "identical"
> fi
> if [ A!=B ]; then
>     echo  "not identical"
> fi
> if [ A==B ]; then
>     echo  "identical"
> fi
>

One equal sign ('=') should be used instead of two equal signs ('==').

--
John Doe

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