diff options
Diffstat (limited to 'src/func.c')
| -rw-r--r-- | src/func.c | 66 |
1 files changed, 63 insertions, 3 deletions
diff --git a/src/func.c b/src/func.c index 5ef9608c1..cfd377eeb 100644 --- a/src/func.c +++ b/src/func.c @@ -16,7 +16,7 @@ ** sqliteRegisterBuildinFunctions() found at the bottom of the file. ** All other code has file scope. ** -** $Id: func.c,v 1.136 2007/01/29 17:58:28 drh Exp $ +** $Id: func.c,v 1.137 2007/03/17 13:27:55 drh Exp $ */ #include "sqliteInt.h" #include <ctype.h> @@ -669,6 +669,65 @@ static void hexFunc( 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. @@ -1081,8 +1140,9 @@ void sqlite3RegisterBuiltinFunctions(sqlite3 *db){ { "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 }, + { "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 |