On 9/18/24 1:05 AM, Oğuz wrote:
On Wed, Sep 18, 2024 at 4:19 AM Steffen Nurpmeso <steffen@xxxxxxxxxx> wrote:It boils down to this: f(){ echo $#;}; set "" "" ""; IFS=x; f $* bash, NetBSD and FreeBSD sh, and ksh88 all agree and print 2. pdksh prints 3 but mksh and oksh print 1. dash, ksh93, yash, and zsh print 0.
It's an implementation difference. The shells that print `0' treat the `may' as `shall' in this sentence from https://pubs.opengroup.org/onlinepubs/9799919799/utilities/V3_chap02.html#tag_19_05_02 "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 2.6.5 Field Splitting." So they immediately expand the $* to nothing. The shells that print `2' don't immediately discard the empty fields and separate them with the first character of IFS. After quote removal and removing the empty fields, since the individual words in $* are subject to additional expansion, you're left with `xx'. When you split that, you get two empty fields. I'm not sure what's going on with the shells that print `1' unless they somehow don't use the first character of IFS to separate the arguments and let multiple sequential delimiters terminate the first field. I assume that pdksh just expands each positional parameter to a quoted empty string and passes them all to f. -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRU chet@xxxxxxxx http://tiswww.cwru.edu/~chet/
