On Thursday 07 April 2016, Bernhard Voelker wrote: > tags 23110 notabug > close 23110 > thanks > > On 04/06/2016 08:19 PM, Ruediger Meier wrote: > > This sounds all true, however then these one should also run > > forever: $ seq 10 0 2 > > > > Man page says: > > INCREMENT is usually positive if FIRST is smaller than LAST, > > and INCREMENT is usually negative if FIRST is greater than > > LAST. > > > > This implicates IMO that seq should try to count _down_ if FIRST > > > LAST and INCREMENT=0 > > Admittedly, the above documentation aims at useful constellations > where seq really operates as a sequence generator - maybe the wording > around "... usually ..." could be improved here. > > In this case, it's not a matter of how increment is treated, but more > when seq ends - which is documented quite clearly both in the --help > output (and therefore in the generated man page), and in the Texinfo > manual: > > http://www.gnu.org/software/coreutils/seq > > The sequence of numbers ends when the sum of the current number > and increment would become greater than last, [...] > > > Moreover I'd say this one does not need to loop endless: > > $ seq 0 0 0 > > Why? The sum of 0+0 will never become _greater_ than 0. > Likewise for the OPs case ("seq -w 2 0 10"): the sum will never > become greater than 10. > > Thus saying, I think this issue is more a confusion regarding the > expectations from the tool. I don't see why an increment of 0 should > be treated special here. > > Therefore, I'm marking this issue as "not a bug", and closing it. > As always, further discussion may continue here, and we can re-open > this issue if needed ... especially if someone proposes a better > wording for the above documentation snippet. ;-)
I understand that this issue is not a bug. But it wouldn't be also not a bug if coreutils would behave like BSD: $ seq 1 0 10 ; echo $? seq: zero increment 1 This is much more useful and safe. Scripts which invoke an endless loop by using seq have almost certainly made something wrong. Endless loop and 100% CPU usage could be avoided. People who _want_ endless trivial "sequences" are using yes(1). cu, Rudi
