On Tue, 22 Mar 2011 16:14:47 -0500, Merlin Moncure wrote about Re: Weird problems with C extension and bytea as input type: [snip] >>> On Tue, Mar 22, 2011 at 8:22 AM, Adrian Schreyer <ams214@xxxxxxxxx> >>> wrote: [snip] >>>> bytea *b = PG_GETARG_BYTEA_P(0); >>>> char *ism; >>>> >>>> ism = function(b); >>>> >>>> PG_RETURN_CSTRING(ism); What is the prototype for function()? If it returns a char * then you will likely have either scope problems, reentrancy problems or memory leaks. If you are going to buy the C++ religion then you usually need to buy it wholesale: do all if your string processing as std::string objects and only return to char * when you revert to C. As a rough example: bytea *b = PG_GETARG_BYTEA_P(0); std::string ism; ism = function(std::string(VARDATA(b), VARSIZE(b)-VARHDRSZ)); PG_RETURN_CSTRING(ism.c_str()); Note that this returns an ASCIIZ string, which is not necessarily the same as the C++ string. You would be better off creating a PostgreSQL text object and then return that. >Well, C++ string constructor is proper in the sense it makes copy of >the source data. however, it's a little weird that you are passing >bytea like this...bytea can contain null and c++ string initialization >stops at any 0 byte. Not so. If the constructor also specifies a length then the data pointer's area is not assumed to be NUL-terminated. >Maybe you should be encoding the data to text (say, to hex) first? Better to use the supplied length in the varlena descriptor. -- Regards, Dave [RLU #314465] *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* dwnoon@xxxxxxxxxxxx (David W Noon) *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
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