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 1.148 2007/05/08 14:39:04 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
/* #include <math.h> */
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

  if( zPattern==0 || zPattern[0]==0 ) return;
  nRep = sqlite3_value_bytes(argv[2]);
  zRep = sqlite3_value_text(argv[2]);
  if( zRep==0 ) return;
  if( nPattern>=nRep ){
    nOut = nStr;
  }else{
    i64 nOut64 = (i64)(nStr/nPattern + 1) * (i64)nRep;
    nOut = ((nOut64>SQLITE_MAX_LENGTH) ? SQLITE_MAX_LENGTH : nOut64);
  }
  zOut = sqlite3_malloc(nOut+1);
  if( zOut==0 ) return;
  loopLimit = nStr - nPattern;  
  for(i=j=0; i<=loopLimit; i++){
    if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){
      zOut[j++] = zStr[i];
    }else{
      if( (j+nRep+loopLimit-i)>SQLITE_MAX_LENGTH ){
        sqlite3_result_error(context, "replace() is too large", -1);
        sqlite3_free(zOut);
        return;
      }
      memcpy(&zOut[j], zRep, nRep);
      j += nRep;
      i += nPattern-1;
    }
  }
  memcpy(&zOut[j], &zStr[i], nStr-i);
  j += nStr - i;

# 2001 September 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing built-in functions.
#
# $Id: func.test,v 1.65 2007/05/08 14:39:04 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Create a table to work with.
#
do_test func-0.0 {

} {00112233445566778899AABBCCDDEEFF}
do_test func-9.11 {
  execsql {SELECT hex(replace('abcdefg','ef','12'))}
} {61626364313267}
do_test func-9.12 {
  execsql {SELECT hex(replace('abcdefg','','12'))}
} {{}}
breakpoint
do_test func-9.13 {
  execsql {SELECT hex(replace('aabcdefg','a','aaa'))}
} {616161616161626364656667}

# Use the "sqlite_register_test_function" TCL command which is part of
# the text fixture in order to verify correct operation of some of
# the user-defined SQL function APIs that are not used by the built-in

} {{This is the larger-main test string}}
do_test func-21.8 {
  execsql {
    SELECT replace("aaaaaaa", "a", "0123456789");
  }
} {0123456789012345678901234567890123456789012345678901234567890123456789}

do_test func-21.9 {
  # Attempt to exploit a buffer-overflow that at one time existed 
  # in the REPLACE function. 
  set ::str "[string repeat A 29998]CC[string repeat A 35537]"
  set ::rep [string repeat B 65536]
  execsql {
    SELECT LENGTH(REPLACE($::str, 'C', $::rep));
  }
} [expr 29998 + 2*65536 + 35537]

# Tests for the TRIM, LTRIM and RTRIM functions.
#
do_test func-22.1 {
  catchsql {SELECT trim(1,2,3)}
} {1 {wrong number of arguments to function trim()}}
do_test func-22.2 {
  catchsql {SELECT ltrim(1,2,3)}