On Thu, Mar 30, 2023 at 9:52 AM Emanuele Torre <torreemanue...@gmail.com> wrote: > > On Thu, Mar 30, 2023 at 07:51:59AM -0600, Felipe Contreras wrote: > > But you can't replicate 'a,b' that way, because b does not have a > > terminator. Obviously we'll want 'b' as a field, therefore one has to > > assume either 1) the end of the string is considered an implicit > > terminator, or 2) the terminator in the last field is optional. > > Neither of these two things is specified in POSIX. > > > > If we consider 1) the end of the string is considered an implicit > > terminator, then 'a' contains a valid field, but then 'a,' contains > > *two* fields. Making these terminators indistinguishable from > > separators. > > I repeatedly disputed this interpretation on IRC by saying that your > reasoning to come to this conclusion is that "',' can terminate a field, > and the end of the string can terminate a field, so ',' at the end is > two terminators".
I did not come to a conclusion, and that is not my reasoning. In IRC you never paid attention to what I was actually saying, so here you are attacking a straw man. > If we extend that reasoning 'a , b' with IFS=' ,' should be split into > four fields because individually ' ', ',', ' ', and the end of string > could all terminate a field. IFS white space characters shall be interpreted differently. That's clear from the specification. > You refuse to acknowledge that it does not make sense to claim that a > comma at the of the string MUST yield an empty last field just because a > ',' and the "end of string" terminator individually can terminate a > field. That is not my claim. > The correct interpretation is that a field is implicitly terminated by > the end of the string if it is not explicitly terminated by a > terminator. Nowhere in the specification does it say that. > How can you say that the current implementation that bash, dash, etc. > use is not compliant to the POSIX specification? I have never said that. > If that is not what you are claiming, how do you think that bash's > implementation of field splitting is not compatible with POSIX > definition since you did not mention it as a possible interpretations? I did not say I think that. My suggestion is that you forget the IRC discussion and focus on what is being said here. -- Felipe Contreras
