[R-pkg-devel] Dialect for shell scripts
Hi all, I'm just bumping this up in case somebody can shed any light on it -- otherwise I will try again to submit this question to r-devel. Regards, Rodrigo
On 12/12/17 06:56, Rodrigo Tobar wrote:
Dear all, During a recent package submission, we were highlighted that some lines in our configure script didn't follow the correct syntax. The lines looked like this: x=$(($y/10)) We were indicated at the time that this is because the statement does not use Bourne shell syntax, which is absolutely true, and also that the manual warns about this, which is true again. So far everything is clear. However, what confuses me is that even when the manual says that "you can include an executable (Bourne) shell script configure in your package" [1], the associated footnote says something slightly different: "The script should only assume a POSIX-compliant /bin/sh" [2]. The footnote goes even further, and links to the POSIX specification of the Shell Command Language [3] (as published by The Open Group), which explicitly includes arithmetic expressions like the one above in its syntax [4]. My question then is: what exact dialect should be considered? Given that the statement above does not work in the Bourne shell, I conclude that the Bourne shell is not POSIX-compliant. That in turn would make the manual ambiguous as to the precise dialect that should be used by our configure scripts, and either the shells used by R should be changed to be POSIX-compliants, or the manual edited to be more precise regarding . Many thanks. Rodrigo [1] https://cran.r-project.org/doc/manuals/r-release/R-exts.html#Configure-and-cleanup [2] https://cran.r-project.org/doc/manuals/r-release/R-exts.html#FOOT25 [3] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html [4] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_04