2017-08-11 13:14 GMT+02:00 Alessandro DE LAURENZIS <[email protected] >:
> Hi Janne, > On Fri 11/08/2017 13:07, Janne Johansson wrote: > >> 0<number> is parsed as octal in places, so 09 would be bogus if octal. >> > [...] > > Thanks for the clarification; does that mean expr(1) can treat 10-base > numbers only? No info in man page on this matter... > Well, I think the default would be for simple math stuff to only use base 10. Then stuff like $(()) should perhaps say it accepts hex,octal or whatever outside of that. $ echo $(( 09 + 1)) ksh: 09 + 1: bad number `09' $ echo $(( 08 + 1)) ksh: 08 + 1: bad number `08' $ echo $(( 07 + 1)) 8 I have used the "skip leading zeros" at times with expr in order to handle possibly empty environment vars with stuff like: sleep $(expr 0$MIGHT_HAVE_VALUE + 1) so that an unset env-var will not make expr treat it like $(expr + 1) which would be an error. -- May the most significant bit of your life be positive.
