diff options
Diffstat (limited to 'src/func.c')
| -rw-r--r-- | src/func.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/src/func.c b/src/func.c index cc74a4ddd..c7af7d679 100644 --- a/src/func.c +++ b/src/func.c @@ -169,6 +169,55 @@ static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ } /* +** Implementation of the instr() function. +** +** instr(haystack,needle) finds the first occurrence of needle +** in haystack and returns the number of previous characters plus 1, +** or 0 if needle does not occur within haystack. +** +** If both haystack and needle are BLOBs, then the result is one more than +** the number of bytes in haystack prior to the first occurrence of needle, +** or 0 if needle never occurs in haystack. +*/ +static void instrFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + const unsigned char *zHaystack; + const unsigned char *zNeedle; + int nHaystack; + int nNeedle; + int typeHaystack, typeNeedle; + int N = 1; + int isText; + + typeHaystack = sqlite3_value_type(argv[0]); + typeNeedle = sqlite3_value_type(argv[1]); + if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return; + nHaystack = sqlite3_value_bytes(argv[0]); + nNeedle = sqlite3_value_bytes(argv[1]); + if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){ + zHaystack = sqlite3_value_blob(argv[0]); + zNeedle = sqlite3_value_blob(argv[1]); + isText = 0; + }else{ + zHaystack = sqlite3_value_text(argv[0]); + zNeedle = sqlite3_value_text(argv[1]); + isText = 1; + } + while( nNeedle<=nHaystack && memcmp(zHaystack, zNeedle, nNeedle)!=0 ){ + N++; + do{ + nHaystack--; + zHaystack++; + }while( isText && (zHaystack[0]&0xc0)==0x80 ); + } + if( nNeedle>nHaystack ) N = 0; + sqlite3_result_int(context, N); +} + +/* ** Implementation of the substr() function. ** ** substr(x,p1,p2) returns p2 characters of x[] beginning with p1. @@ -1536,6 +1585,7 @@ void sqlite3RegisterGlobalFunctions(void){ AGGREGATE(max, 1, 1, 1, minmaxStep, minMaxFinalize ), FUNCTION2(typeof, 1, 0, 0, typeofFunc, SQLITE_FUNC_TYPEOF), FUNCTION2(length, 1, 0, 0, lengthFunc, SQLITE_FUNC_LENGTH), + FUNCTION(instr, 2, 0, 0, instrFunc ), FUNCTION(substr, 2, 0, 0, substrFunc ), FUNCTION(substr, 3, 0, 0, substrFunc ), FUNCTION(abs, 1, 0, 0, absFunc ), |