"Jordan Brown (Sun)" wrote: > Roland Mainz wrote: > > Ok... two questions: > > 1. How can a Bourne[1] shell script get the number of values in a > > property ? > > 2. How can I get value number <n> from a Bourne[1] shell script ? > > I love sh puzzles... > > Ignoring the possibility of feeding it through awk or something like > that, how about... > > set -- `svccfg -s svc:/application/mydaemon listprop my/prop` > shift 2 > echo $# > echo $1 > echo $2 > ... > ?
Yes... I did something similar with "read -A myarrayvar" in ksh93... but it's still a bit scary since it relies on field splitting via IFS (e.g. either set to the default value or IFS=' ') which itself is tricky when the script explicitly set IFS='' as security measure against code injection attacks (see link to David Korn's recommendations "how to write secure scripts"). > Processing the quoting right is left as an exercise for the reader (but, > hint: I suspect that "eval" is your friend). Except that "eval" is a _SERIOUS_ security risk (short: attributary code execution) and should be avoided at all costs (you can find David Korn's recommendation for "eval" in http://mail.opensolaris.org/pipermail/shell-discuss/2007-June/000993.html ; also note that almost every mordern shell added other ways to replace the most common consumers for "eval", e.g. ksh93's original design added the "nameref" datatype to replace things like $ foo="abc" ; eval "${foo}=\"${value}\"" # by $ nameref foo="abc" ; abc="${value}" #) ... and it should even more avoided in the case of SMF and setuid/setgid scripts to avoid things like "priviledge escalation" ... ... one question is still open: How do I know when a property is _supposed_ to have only exactly one value or when it _may_ have multiple values by design ? The XML file can define this via "astring_list" to indicate that multiple values may follow... but I don't see a way to seperate between both cases on the consumer side via /usr/bin/svcprop ... ;-( ---- Bye, Roland -- __ . . __ (o.\ \/ /.o) roland.mainz at nrubsig.org \__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer /O /==\ O\ TEL +49 641 7950090 (;O/ \/ \O;)
