On Fri, 2020-12-04 at 18:07 +0100, Ard Biesheuvel wrote: > On Fri, 4 Dec 2020 at 18:06, <laniel_francis@xxxxxxxxxxxxxxxxxxx> > wrote: > > From: Francis Laniel <laniel_francis@xxxxxxxxxxxxxxxxxxx> > > > > The two functions indicates if a string begins with a given prefix. > > The only difference is that strstarts() returns a bool while > > str_has_prefix() > > returns the length of the prefix if the string begins with it or 0 > > otherwise. > > > > Why? I think I can answer that. If the conversion were done properly (which it's not) you could get rid of the double strings in the code which are error prone if you update one and forget another. This gives a good example: 3d739c1f6156 ("tracing: Use the return of str_has_prefix() to remove open coded numbers"). so in your code you'd replace things like if (strstarts(option, "rgb")) { option += strlen("rgb"); ... with len = str_has_prefix(option, "rgb"); if (len) { option += len ... Obviously you also have cases where strstart is used as a boolean with no need to know the length ... I think there's no value to converting those. James