SQLite

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.178 2007/12/07 18:39:05 drh Exp $
** $Id: func.c,v 1.179 2007/12/10 18:07:21 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

** For LIKE and GLOB matching on EBCDIC machines, assume that every
** character is exactly one byte in size.  Also, all characters are
** able to participate in upper-case-to-lower-case mappings in EBCDIC
** whereas only characters less than 0x80 do in ASCII.
*/
#if defined(SQLITE_EBCDIC)
# define sqlite3Utf8Read(A,B,C)  (*(A++))
# define UpperToLower(A)         A = sqlite3UpperToLower[A]
# define GlogUpperToLower(A)     A = sqlite3UpperToLower[A]
#else
# define UpperToLower(A)         if( A<0x80 ){ A = sqlite3UpperToLower[A]; }
# define GlogUpperToLower(A)     if( A<0x80 ){ A = sqlite3UpperToLower[A]; }
#endif

static const struct compareInfo globInfo = { '*', '?', '[', 0 };
/* The correct SQL-92 behavior is for the LIKE operator to ignore
** case.  Thus  'a' LIKE 'A' would be true. */
static const struct compareInfo likeInfoNorm = { '%', '_',   0, 1 };
/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator

        while( *zString && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
          SQLITE_SKIP_UTF8(zString);
        }
        return *zString!=0;
      }
      while( (c2 = sqlite3Utf8Read(zString,0,&zString))!=0 ){
        if( noCase ){
          UpperToLower(c2);
          UpperToLower(c);
          GlogUpperToLower(c2);
          GlogUpperToLower(c);
          while( c2 != 0 && c2 != c ){
            c2 = sqlite3Utf8Read(zString, 0, &zString);
            UpperToLower(c2);
            GlogUpperToLower(c2);
          }
        }else{
          while( c2 != 0 && c2 != c ){
            c2 = sqlite3Utf8Read(zString, 0, &zString);
          }
        }
        if( c2==0 ) return 0;

        return 0;
      }
    }else if( esc==c && !prevEscape ){
      prevEscape = 1;
    }else{
      c2 = sqlite3Utf8Read(zString, 0, &zString);
      if( noCase ){
        UpperToLower(c);
        UpperToLower(c2);
        GlogUpperToLower(c);
        GlogUpperToLower(c2);
      }
      if( c!=c2 ){
        return 0;
      }
      prevEscape = 0;
    }
  }