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 1.137 2007/03/17 13:27:55 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
/* #include <math.h> */
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

    unsigned char c = *pBlob;
    *(z++) = hexdigits[(c>>4)&0xf];
    *(z++) = hexdigits[c&0xf];
  }
  *z = 0;
  sqlite3_result_text(context, zHex, n*2, sqlite3_free);
}

/*
** The replace() function.  Three arguments are all strings: call
** them A, B, and C. The result is also a string which is derived
** from A by replacing every occurance of B with C.  The match
** must be exact.  Collating sequences are not used.
*/
static void replaceFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const unsigned char *zStr;        /* The input string A */
  const unsigned char *zPattern;    /* The pattern string B */
  const unsigned char *zRep;        /* The replacement string C */
  unsigned char *zOut;              /* The output */
  int nStr;                /* Size of zStr */
  int nPattern;            /* Size of zPattern */
  int nRep;                /* Size of zRep */
  int nOut;                /* Maximum size of zOut */
  int loopLimit;           /* Last zStr[] that might match zPattern[] */
  int i, j;                /* Loop counters */

  assert( argc==3 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ||
      sqlite3_value_type(argv[1])==SQLITE_NULL ||
      sqlite3_value_type(argv[2])==SQLITE_NULL ){
    return;
  }
  nStr = sqlite3_value_bytes(argv[0]);
  zStr = sqlite3_value_text(argv[0]);
  nPattern = sqlite3_value_bytes(argv[1]);
  zPattern = sqlite3_value_text(argv[1]);
  nRep = sqlite3_value_bytes(argv[2]);
  zRep = sqlite3_value_text(argv[2]);
  if( nPattern>=nRep ){
    nOut = nStr;
  }else{
    nOut = (nStr/nPattern + 1)*nRep;
  }
  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{
      memcpy(&zOut[j], zRep, nRep);
      j += nRep;
      i += nPattern-1;
    }
  }
  memcpy(&zOut[j], &zStr[i], nStr-i);
  j += nStr - i;
  assert( j<=nOut );
  zOut[j] = 0;
  sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
}


#ifdef SQLITE_SOUNDEX
/*
** Compute the soundex encoding of a word.
*/
static void soundexFunc(
  sqlite3_context *context,

    { "randomblob",         1, 0, SQLITE_UTF8,    0, randomBlob },
    { "nullif",             2, 0, SQLITE_UTF8,    1, nullifFunc },
    { "sqlite_version",     0, 0, SQLITE_UTF8,    0, versionFunc},
    { "quote",              1, 0, SQLITE_UTF8,    0, quoteFunc  },
    { "last_insert_rowid",  0, 1, SQLITE_UTF8,    0, last_insert_rowid },
    { "changes",            0, 1, SQLITE_UTF8,    0, changes    },
    { "total_changes",      0, 1, SQLITE_UTF8,    0, total_changes },
    { "replace",            3, 0, SQLITE_UTF8,    0, replaceFunc       },
#ifdef SQLITE_SOUNDEX
    { "soundex",            1, 0, SQLITE_UTF8, 0, soundexFunc},
#endif
#ifndef SQLITE_OMIT_LOAD_EXTENSION
    { "load_extension",     1, 1, SQLITE_UTF8,    0, loadExt },
    { "load_extension",     2, 1, SQLITE_UTF8,    0, loadExt },
#endif

# 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 1.58 2007/03/17 13:27:56 drh Exp $

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

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

  } {
    incr i
    do_test func-20.$i {
      execsql {SELECT soundex($name)}
    } $sdx
  }
}

# Tests of the REPLACE function.
#
do_test func-21.1 {
  catchsql {
    SELECT replace(1,2);
  }
} {1 {wrong number of arguments to function replace()}}
do_test func-21.2 {
  catchsql {
    SELECT replace(1,2,3,4);
  }
} {1 {wrong number of arguments to function replace()}}
do_test func-21.3 {
  execsql {
    SELECT typeof(replace("This is the main test string", NULL, "ALT"));
  }
} {null}
do_test func-21.4 {
  execsql {
    SELECT typeof(replace(NULL, "main", "ALT"));
  }
} {null}
do_test func-21.5 {
  execsql {
    SELECT typeof(replace("This is the main test string", "main", NULL));
  }
} {null}
do_test func-21.6 {
  execsql {
    SELECT replace("This is the main test string", "main", "ALT");
  }
} {{This is the ALT test string}}
do_test func-21.7 {
  execsql {
    SELECT replace("This is the main test string", "main", "larger-main");
  }
} {{This is the larger-main test string}}
do_test func-21.8 {
  execsql {
    SELECT replace("aaaaaaa", "a", "0123456789");
  }
} {0123456789012345678901234567890123456789012345678901234567890123456789}



finish_test