Re: [Qemu-devel] [PULL 14/16] qemu-img: Improve error messages

[Markus Armbruster]

Jeff Cody <address@hidden> writes:

> On Wed, Apr 23, 2014 at 12:04:49PM +0200, Kevin Wolf wrote:
>> From: Fam Zheng <address@hidden>
>> 
>> Previously, when there is a user error in argv parsing, qemu-img prints
>> help text and exits.
>> 
>> Add an error_exit function to print a helpful error message and a hint
>> to run 'qemu-img --help' for more information.
>> 
>> As a bonus, "qemu-img <cmd> --help" now has a more reasonable exit code
>> 0.
>> 
>> In the future the help text should be split by sub command, and only
>> print the information for the specified command.
>> 
>> Signed-off-by: Fam Zheng <address@hidden>
>> Signed-off-by: Kevin Wolf <address@hidden>
>> ---
>
> This breaks 'qemu-img --help':
>
> ./qemu-img --help
> qemu-img: Command not found: --help
> Try 'qemu-img --help' for more information
>
> See below:
>
>
> <snip>
>   
>>      bs = bdrv_new_open("image", filename, fmt,
>> @@ -2781,8 +2799,9 @@ int main(int argc, char **argv)
>>  
>>      qemu_init_main_loop();
>>      bdrv_init();
>> -    if (argc < 2)
>> -        help();
>> +    if (argc < 2) {
>> +        error_exit("Not enough arguments");
>> +    }
>
> As an aside, are we sure we want './qemu-img' with no arguments to not
> return the full help message?

I hate it when programs spew out screenfulls of help on incorrect usage.
Three lines are the limit for me: error message, brief help, how to get
full help.

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