[GitHub] incubator-trafodion pull request #842: [TRAFODION-2353] support of the regex...

[DaveBirdsall]

Github user DaveBirdsall commented on a diff in the pull request:

    https://github.com/apache/incubator-trafodion/pull/842#discussion_r89157253
  
    --- Diff: core/sql/exp/exp_like.cpp ---
    @@ -477,6 +501,51 @@ ex_like_clause_base::processNulls(char *op_data[], 
CollHeap *heap,
       return ex_expr::EXPR_OK;
     }
     
    +
    +ex_expr::exp_return_type ExRegexpClauseChar::eval(char *op_data[],
    +                                         CollHeap* exHeap,
    +                                         ComDiagsArea** diagsArea)
    +{
    +  NABoolean matchFlag = true;
    +  Lng32 len1 = getOperand(1)->getLength(op_data[-MAX_OPERANDS+1]);
    +  Lng32 len2 = getOperand(2)->getLength(op_data[-MAX_OPERANDS+2]);
    +  regex_t reg;
    +  regmatch_t pm[1];
    +  const size_t nmatch = 1;
    +  Lng32 cflags, z;
    +  char * pattern;
    +  char *srcStr= new (exHeap) char[len1+1];
    +
    +  cflags = REG_EXTENDED|REG_NEWLINE;
    +  pattern = new (exHeap) char[len2+1];
    +  pattern[len2]=0;
    +  srcStr[len1]=0;
    +
    +  str_cpy_all(pattern, op_data[2], len2);
    +  str_cpy_all(srcStr, op_data[1], len1);
    +
    +  z = regcomp(&reg, pattern, cflags);
    +
    +  if (z != 0){
    +    //ERROR
    +    ExRaiseSqlError(exHeap, diagsArea, EXE_BAD_ARG_TO_MATH_FUNC);
    +    **diagsArea << DgString0("REGEXP");
    +    return ex_expr::EXPR_ERROR;
    +  }
    + 
    +  z = regexec(&reg,srcStr , nmatch, pm, 0);
    --- End diff --
    
    From the regexec man page, it looks like regexec returns 0 for a successful 
match, REG_NOMATCH for a successful mismatch, and an error code for an error. 
We need to check for the error and report it (for example, using regerror() to 
obtain an error string).


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---