118 lines
2.1 KiB
C
118 lines
2.1 KiB
C
/* $Header: /cvsroot/pgsql/contrib/soundex/Attic/soundex.c,v 1.10 2001/02/10 02:31:26 tgl Exp $ */
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#include "postgres.h"
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#include <ctype.h>
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#include "fmgr.h"
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#include "utils/builtins.h"
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Datum text_soundex(PG_FUNCTION_ARGS);
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static void soundex(const char *instr, char *outstr);
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#define SOUNDEX_LEN 4
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#define _textin(str) DirectFunctionCall1(textin, CStringGetDatum(str))
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#define _textout(str) DatumGetPointer(DirectFunctionCall1(textout, PointerGetDatum(str)))
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#ifndef SOUNDEX_TEST
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/*
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* SQL function: text_soundex(text) returns text
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*/
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PG_FUNCTION_INFO_V1(text_soundex);
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Datum
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text_soundex(PG_FUNCTION_ARGS)
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{
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char outstr[SOUNDEX_LEN + 1];
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char *arg;
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arg = _textout(PG_GETARG_TEXT_P(0));
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soundex(arg, outstr);
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PG_RETURN_TEXT_P(_textin(outstr));
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}
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#endif /* not SOUNDEX_TEST */
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/* ABCDEFGHIJKLMNOPQRSTUVWXYZ */
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static const char *soundex_table = "01230120022455012623010202";
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#define soundex_code(letter) soundex_table[toupper((unsigned char) (letter)) - 'A']
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static void
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soundex(const char *instr, char *outstr)
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{
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int count;
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AssertArg(instr);
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AssertArg(outstr);
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outstr[SOUNDEX_LEN] = '\0';
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/* Skip leading non-alphabetic characters */
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while (!isalpha((unsigned char) instr[0]) && instr[0])
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++instr;
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/* No string left */
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if (!instr[0])
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{
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outstr[0] = (char) 0;
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return;
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}
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/* Take the first letter as is */
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*outstr++ = (char) toupper((unsigned char) *instr++);
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count = 1;
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while (*instr && count < SOUNDEX_LEN)
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{
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if (isalpha((unsigned char) *instr) &&
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soundex_code(*instr) != soundex_code(*(instr - 1)))
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{
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*outstr = soundex_code(instr[0]);
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if (*outstr != '0')
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{
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++outstr;
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++count;
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}
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}
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++instr;
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}
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/* Fill with 0's */
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while (count < SOUNDEX_LEN)
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{
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*outstr = '0';
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++outstr;
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++count;
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}
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}
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#ifdef SOUNDEX_TEST
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int
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main (int argc, char *argv[])
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{
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if (argc < 2)
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{
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fprintf(stderr, "usage: %s string\n", argv[0]);
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return 1;
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}
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else
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{
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char output[SOUNDEX_LEN + 1];
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soundex(argv[1], output);
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printf("soundex(%s) = %s\n", argv[1], output);
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return 0;
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}
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}
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#endif /* SOUNDEX_TEST */
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