Dear Robert, all. Robert Elz wrote in <39.1724620...@jacaranda.noi.kre.to>: | Date: Sun, 25 Aug 2024 04:08:58 +0200 | From: Steffen Nurpmeso <stef...@sdaoden.eu> | Message-ID: <20240825020858.nrX4pFTm@steffen%sdaoden.eu> | || (The only thinkable answer is that the step that my MUA does, || namely resolving $* as a single string first, does not happen, || right? | |That's correct. When (first) expanding $* the value of IFS |is irrelevant, except for expansions where field splitting won't |later be performed (ie: never would be performed, regardless of |the value of IFS) - eg: VAR=$* or more commonly "$*". | |After the fields have been expanded, then the results of those |expansions are subject to field splitting, for which IFS is |relevant. | |That is, given | | set -- a b c | |$* produces 3 fields, "a" "b" and "c" (not quoted of course) |which are then subject (individually) to field splitting. |If we had IFS=b then the middle field would turn into nothing, |leaving just "a" and "c". | || I really have to carefully read the standard on Monday.) | |For this see XCU 2.5.2, the descriptions of the expansions of |the special parameters, $@ and $* are the first two listed. |When unquoted, they're identical: | | Expands to the positional parameters, starting from one, initially | producing one field for each positional parameter that is set. When | the expansion occurs in a context where field splitting will be | performed, any empty fields may be discarded and each of the non-empty | fields shall be further split as described in Section 2.6.5. | |After that, when the expansion is in a context where field splitting |won't be performed, then $* and $@ are processed differently - with |$@ only being defined in a few cases in this circumstance. 2.6.5 |says how IFS is used to (potentially) break those fields up info smaller |fields. | |For $* in a non-field-splitting context, it goes on to say: | | When the expansion occurs in a context where field splitting will | not be performed, the initial fields shall be joined to form a | single field with the value of each parameter separated by the first | character of the IFS variable if IFS contains at least one character, | or separated by a <space> if IFS is unset, or with no separation if | IFS is set to a null string. | |If that happens, since we know we're in a context where field splitting |doesn't happen, we're done (just quote removal to follow - as not doing |field splitting usually also means not doing pathname expansion - though |some shells will do pathname expansion on the word after a redirect \ |operator, |sometimes.)
I will not get to this today, it is 2 o'clock in the morning and i am happy shall i lay at 6.30 o'clock. Thanks for your response, i will act accordingly. Yes, here we "exploded" $* and $@ yet only if in double quotes, otherwise they are looked up as normal variables (then subject to the new word splitting). Thank you very much for your answer. |kre --End of <39.1724620...@jacaranda.noi.kre.to> --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt)
