Is Generic Match

Summary

The following are the RPG/LE fully free-form definitions and instructions needed for using the Is Generic Match service procedure. This service procedure simply allows the caller to determine if a character string is a generic or partial match for another character string—or not.

By Dave Clark

Service Prototype

Place the following in a separate copybook for inclusion in both the caller and the service program source members.

**free

//==============================================================================
// This procedure provides a Boolean result indicating whether or not the
// first parameter is a generic (or partial) match of a second parameter.  
// Note that both kinds of matches are supported -- generic or partial --
// by comparing the first part of the second parameter based on the
// length of the first parameter (after stripping any trailing asterisk).
//==============================================================================
dcl-pr GenUtl_isGenericMatch    ind;
  pNeedle               varchar(50) const   options(*trim);
  pHayStack             varchar(50) const   options(*trim);
end-pr;

Service Procedure

Place the following in a service program source member.

**free
ctl-opt NoMain AlwNull(*UsrCtl) Debug Option(*SrcStmt:*NoDebugIo)
        DatFmt(*ISO) TimFmt(*ISO);

//==============================================================================
// This procedure provides a Boolean result indicating whether or not the
// first parameter is a generic (or partial) match of a second parameter.  
// Note that both kinds of matches are supported -- generic or partial --
// by comparing the first part of the second parameter based on the
// length of the first parameter (after stripping any trailing asterisk).
//==============================================================================
dcl-proc GenUtl_isGenericMatch  export;
  dcl-pi *n             ind;
    pNeedle             varchar(50) const   options(*trim);
    pHayStack           varchar(50) const   options(*trim);
  end-pi;

  dcl-s iNeedle         like(pNeedle);

  if GenUtl_SuffixString(pNeedle:1) = '*'; // if generic indicator present
    iNeedle = %subst(pNeedle: 1: %len(pNeedle)-1); // strip it off
  else;                                // else
    iNeedle = pNeedle;                 // take the string as-is
  endif;

  if %len(iNeedle) > %len(pHayStack);  // if needle bigger than haystack
    return *off;                       // then a compare is not possible
  endif;

  return (iNeedle = %subst(pHayStack:1:%len(iNeedle))); // return result
end-proc;

References

• GenUtl_SuffixString service procedure