Re: [Bug-ddrescue] Suggestions to rename "logfile"

[Florian Sedivy]

Hello Antonio!

Antonio Diaz Diaz wrote:
>> My proposition is "mapfile" to replace "logfile"
> 
> Ok, you have convinced me. I'll prepare rc3 with "mapfile" ASAP.

I feel honored. Time to mention that it was Robert Trevellyan who first 
proposed "mapfile". 

>> But I am with Adrien and Felix for making it mandatory. This is the
>> one most common error, and it is easy to prevent. I propose to allow
>> a single "-" as 3rd parameter to operate without a logfile. That way
>> the experienced user has only minimal inconvenience when making
>> logless runs.
> 
> "minimal inconvenience" is subjective. I, for example, use ddrescue as a 
> replacement for dd and find the '--force' option enough of an inconvenience 
> that I am sometimes tempted to remove it.
> 
> The main reason why I keep '--force' is because it may prevent a catastrophic 
> error (overwriting data in the destination drive). But the lack of a logfile 
> just can make the rescue longer, and perhaps reduce the amount of data 
> rescued, for those who think they are cleverer than the fine manual.

That's why I tried to find something shorter than --no-mapfile to override a 
mandatory mapfile. More like a fast trick for the expert, and yes, I also use 
ddrescue instead of dd in most cases. 
> 
> Finally, I think that using a single "-" to mean anything other that reading 
> from stdin or writing to stdout is confusing to say the least.

You are completely right, that was a bad idea. So I want to find another 
convenient way for the experienced user to run without the mandatory mapfile. 

Single character replacements for the mapfile parameter are difficult, because 
in POSIX every character except "/" and NUL could theoretically be a filename. 
So it must be something, nobody in their right minds would ever want to use as 
a filename. Anyway, ddrescue should always show a warning when running without 
a mapfile. 
"."     although possible, this is a valid directory, so it would be a little 
bit of a dirty hack
"+"     possible, except for a plus-sign being counter-intuitive when actually 
leaving something away
"="     why not?
"_"     why not?

Double character replacements: 
-z or similar   bad - anything that looks like an option would be confusing 
when used to replace a positional parameter
--              why not? double hyphen is sometimes used to separate options 
from positional parameters
"" or ''        Passing an empty string to bypass the requirement would be 
quite elegant. Only risk is, when you pass an unintentionally empty variable as 
mapfile parameter, you might not notice the mistake. 

Use an option to make the mapfile optional. Personally I'd prefer a replacement 
to an option. 
-f, --force                     bad - should not have any additional meaning 
than it has now
-z or similar           I don't think this really justifies introducing a new 
option            
-L, --loose-domain      Could nicely serve this second purpose. Users working 
with loose domain mapfiles are probably experienced enough not to need the 
safeguard of a mandatory mapfile. 

Something there you like?
Regards, Florian