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From: Andrej Picej <andrej.picej@norik.com>
To: barebox@lists.infradead.org
Subject: Re: Not successful if statements returning error code
Date: Tue, 27 Jul 2021 07:20:57 +0200
Message-ID: <e1659342-6028-b76a-9445-4f96d3c54c8b@norik.com> (raw)
In-Reply-To: <4e1aa199-a5fa-2ad5-80cb-ef3cf86fd174@norik.com>

Just saw that I forgot to mention the main reason, why this is important.
We have a couple of boot scripts which end with if statements. If 
conditions of these if statements are not met then the boot script 
returns error code and the booting process is broken:

> Running script '/env/boot/mmc' failed: error -1
> Booting entry 'mmc' failed
> Nothing bootable found

BR,
Andrej

On 23. 07. 21 12:18, Andrej Picej wrote:
> Hi all,
> 
> I have a question about Hush shell and the use of its conditional 
> statements.
> We have come upon an interesting behaviour with its return values.
> 
> If the condition of the if statement is not true then the return value 
> is 1 (error code), and if the condition is true the return value is 0 
> (success).
> 
> Simple test:
>> #!/bin/sh
>> if [ 0 -gt 1 ]; then
>>   echo "0 gt 1, Ret: $?"
>> fi
>> echo "Ret: $?"
>>
>> if [ 2 -gt 1 ]; then
>>   echo "2 gt 1, Ret: $?"
>> fi
>> echo "Ret: $?"
> 
> Output:
>> Ret: 1
>> 2 gt 1, Ret: 0
>> Ret: 0
> 
> This means that if, for example the first if statement (where condition 
> is not met) would be at the end of a script the return value of that 
> whole script would be 1 (error code).
> I don't think this follows standard shell behaviour. If if statement 
> condition is not met this doesn't mean that the return value should be 
> an error code, right?
> Using other shells (bash for example) we can see that the returned value 
> in both cases is 0, which is expected (IMO).
> 
> This behaviour is not new to the Hush or barebox as I could reproduce it 
> on various previous barebox versions (2013.08.0, 2017.12.0 and 2019.11.0).
> 
> Of course, this problem can be easily avoided if at the end of every 
> script we use explicit exit 0. This is doable, but a little annoying.
> 
> Although this is not a deal-breaker for us, I was wondering what is the 
> reason behind this? How do you get around this and are there any plans 
> to fix/modify this in the future so it follows the behaviour of other 
> shells?
> 
> Thank you for your answer.
> 
> Best regards,
> Andrej
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox

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  reply	other threads:[~2021-07-27  7:17 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-23 10:18 Andrej Picej
2021-07-27  5:20 ` Andrej Picej [this message]
2021-07-28  8:56 ` Ahmad Fatoum
2021-07-28  9:38   ` Denis Osterland-Heim
2021-07-29  9:22     ` Ahmad Fatoum
2021-07-29  9:48       ` Denis Osterland-Heim
2021-08-09 10:54         ` Ahmad Fatoum

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