Isabella Stephens <istephens@xxxxxxxxxxxxx> writes: > This is the existing behaviour. -L10,-20 for example will blame the > first 10 lines of a file, it will not fail. My patch doesn't change > this. The case I am discussing is -L,-20 which at the moment blames > the first line of the file. Trying to go backwards from the start of > a file should be considered invalid, in my opinion, however I don't > feel strongly about it - I don't expect this case is common in > practice. I tend to think that -L,-20 is a sloppy spelling of -L1,-20 (i.e. anything omitted gets reasonable default, and for something that specifies both ends, i.e. "<begin>,<end>", the beginning and the end of the file would be such reasonable default, respectively), and as such I would imagine that the user would expect the same behaviour as -L1,-20. If the longhand version gives only the first line (i.e. show up to 20 lines ending at line #1), I'd say that sounds sensible. Or does -L1,-20 show nothing and consider the input invalid? If so, then sure, -L,-20 should also be an invalid input.
