PostgreSQL How do I convert struct text to plain *char in C functions?

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2 answers

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                          I'm using my internal C function which doesn't know about postgresql's text struct, how do I pass text argument when char * expected?



    #include 
    #include 
    #include "postgres.h"
    #include "fmgr.h"
    
    #ifdef PG_MODULE_MAGIC
    PG_MODULE_MAGIC;
    #endif
    
    PG_FUNCTION_INFO_V1(fun);
    
    Datum fun(PG_FUNCTION_ARGS)
    {
    	text 	*str1, *str2;
    
    	str1 = PG_GETARG_TEXT_P(0);
    	str2 = PG_GETARG_TEXT_P(1);
    
    	FILE *fp = fopen("/tmp/fun.log", "w");
    	fprintf(fp, "%s\n", VARDATA_ANY(str1));
    	fprintf(fp, "%s\n", VARDATA_ANY(str2));
    	fclose(fp);
    
    	PG_RETURN_INT32(0);
    }


Here's what xxd sees in log file:



    0000000: 666f 6f74 6261 6c6c c88d 7409 70d3 6b09  football..t.p.k.
    0000010: 080a 7a6f 6f6d 0a                        ..zoom.

After executing:

    SELECT * FROM fun('football','zoom');

Why junk after football?
                        

Asked by Moe (41 rep)

Jan 18, 2013, 02:12 PM
Last activity: Feb 3, 2020, 01:28 PM

PostgreSQL How do I convert struct text to plain *char in C functions?

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