Why not do both? Use lengths and make sure the string is null terminated. That's how std::string works in C++ where you can call c_str() to return a null terminated string.
On 29/06/2013, at 9:15 AM, zMan <[email protected]> wrote: > Right, but these kids don't seem to be. The argument I'm getting is "OK, > but even if we pass an explicit length, people will assume the return is > null-terminated". I say, "They'll learn"... > > > On Fri, Jun 28, 2013 at 8:29 PM, Charles Mills <[email protected]> wrote: > >> Yes, character arrays and an explicit length. C programmers are quite used >> to this, viz. memcpy() etc. >> >> Charles >> >> -----Original Message----- >> From: IBM Mainframe Discussion List [mailto:[email protected]] On >> Behalf Of zMan >> Sent: Friday, June 28, 2013 12:53 PM >> To: [email protected] >> Subject: Theology question: Parameter formats >> >> Suppose you're defining an API, to be callable from multiple languages, >> including C. You believe/assume that C will be the most common language on >> non-z platforms (probably reasonable, FSVO "reasonable"), but you also need >> to be callable on z. >> >> Would you: >> a) Design the API to pass data/length pairs >> b) Use null-terminated strings to keep the C people happy, and have to >> create some sort of layer for languages like COBOL to keep usage from that >> world sane? >> >> (Yes, I know about z' variables in COBOL, but people aren't used to and in >> my experience aren't fond of those. And there are a lot of languages out >> there to consider besides COBOL!) >> >> My contention is that C folks can surely understand the concept of passing >> a >> length, especially since C validates parameters -- that is, if a C person >> might expect to call SOMEFUNCTION(char*, char*) >> >> and instead the function definition is >> SOMEFUNCTION(char*, int*, char*, int*) >> they shouldn't exactly be confused. Surely they understand the *concept* of >> a length. >> >> But people are whining: "But this is how C works -- that's what strings >> are!". >> >> How do most other APIs deal with this? I've not really written applications >> this century (or, to be honest, the last one) -- always done systems stuff. >> >> As part of this discussion, I've had the epiphany that people don't >> *expect* to be able to call existing code from random languages--they think >> there will need to be some kind of shim layer. So they're quite surprised >> that as z folks, we expect an API to be callable from pretty well any >> language (modulo pathologies like COBOL's inability to do dynamic memory >> allocation). >> >> ---------------------------------------------------------------------- >> For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to [email protected] with the message: INFO IBM-MAIN >> > > > > -- > zMan -- "I've got a mainframe and I'm not afraid to use it" > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
