Re: `if $(cmd);' is a positive when there's no output from cmd

[Herculano Einloft]

Em (02:25:11), Andreas Schwab escreveu: 

> 
>> Hey all, 
>> 
>> $ if $(echo string >/dev/null); then echo true; fi 
>> true 
>> 
>> This should be a syntax error 
> 
>No, it is a perfectly valid command, syntactically. That the command 
>substitution expands to nothing has no significance any more once the 
>command is parsed, just like shell meta characters resulting from 
>expansions are taken literally. 
> 
>Andreas. 

That's not true.. try: 

$ echo $(echo \*) 

or 

$ a=*; echo "$a"; echo $a 

for illustration. 

Regards