added the "startwith" property-filter comparison operation

1 files changed, 31 insertions, 0 deletions

diff --git a/stringbuf.c b/stringbuf.c
index 1f6d6316..738a1f81 100755
--- a/stringbuf.c
+++ b/stringbuf.c
@@ -371,6 +371,37 @@ int rsCStrCStrCmp(rsCStrObj *pCS1, rsCStrObj *pCS2)
 }
 
 
+/* check if a CStr object starts with a sz-type string. This function
+ * is initially written to support the "startswith" property-filter
+ * comparison operation. Maybe it also has other needs.
+ * rgerhards 2005-09-26
+ */
+int rsCStrStartsWithSzStr(rsCStrObj *pCS1, char *psz, int iLenSz)
+{
+	rsCHECKVALIDOBJECT(pCS1, OIDrsCStr);
+	assert(psz != NULL);
+	assert(iLenSz == strlen(psz)); /* just make sure during debugging! */
+	if(pCS1->iStrLen >= iLenSz) {
+		/* we are using iLenSz below, because we need to check
+		 * iLenSz characters at maximum (start with!)
+		 */
+		if(iLenSz == 0)
+			return 0; /* yes, it starts with a zero-sized string ;) */
+		else {  /* we now have something to compare, so let's do it... */
+			register int i;
+			for(i = 0 ; i < iLenSz ; ++i) {
+				if(pCS1->pBuf[i] != psz[i])
+					return pCS1->pBuf[i] - psz[i];
+			}
+			/* if we arrive here, the string actually starts with psz */
+			return 0;
+		}
+	}
+	else
+		return -1; /* pCS1 is less then psz */
+}
+
+
 /* compare a rsCStr object with a classical sz string.  This function
  * is almost identical to rsCStrZsStrCmp(), but it also takes an offset
  * to the CStr object from where the comparison is to start.