diff --git a/doc/helianthus-doc-ru.odt b/doc/helianthus-doc-ru.odt
index eda0ced..c199e6d 100644
Binary files a/doc/helianthus-doc-ru.odt and b/doc/helianthus-doc-ru.odt differ
diff --git a/src/common.c b/src/common.c
index d6daf84..b20fbf7 100644
--- a/src/common.c
+++ b/src/common.c
@@ -11,6 +11,7 @@ HeliArray heliObjectsSet;
 
 
 struct _Directory {
+	size_t pathLen;
 	HeliArray files;
 };
 
@@ -44,21 +45,68 @@ void rotateVector(double *x, double *y, double angle) {
 	if (y) *y = xx*s + yy*c;
 }
 
-	
-Directory openDirectory(const char *path) {
+Directory openDirectoryEx(
+	const char *path,
+	const char *prefix,
+	const char *suffix,
+	int caseSensitive,
+	int showFiles,
+	int showDirectories )
+{
 	if (!heliInitialized) return NULL;
+	if (!path) return NULL;
 	
 	DIR *dir = opendir(path);
 	if (!dir) return NULL;
 	
 	Directory d = calloc(1, sizeof(*d));
 	
+	d->pathLen = strlen(path);
+	size_t prefixLen = prefix ? strlen(prefix) : 0u;
+	size_t suffixLen = suffix ? strlen(suffix) : 0u;
+	
+	size_t bufLen = d->pathLen + 1024;
+	char *buf = calloc(1, bufLen);
+	strcpy(buf, path);
+	if (d->pathLen > 0 && buf[d->pathLen - 1] != '\\' && buf[d->pathLen - 1] != '/') {
+		char lastSlash = '/';
+		for(const char *c = buf; *c; ++c)
+			if (*c == '\\' || *c == '/') lastSlash = *c;
+		buf[d->pathLen++] = lastSlash;
+	}
+	
 	struct dirent *ent;
 	while((ent = readdir(dir)) != NULL) {
 		if ( !ent->d_name[0]
 		  || strcmp(ent->d_name, ".") == 0
 		  || strcmp(ent->d_name, "..") == 0 ) continue;
-		heliStringmapAdd(&d->files, ent->d_name, NULL, NULL);
+		
+		if (prefixLen) {
+			if ( caseSensitive ? strncmp(prefix, ent->d_name, prefixLen)
+				               : heliStringCompareNCi(prefix, ent->d_name, prefixLen) )
+				continue;
+		}
+		
+		size_t nameLen = strlen(ent->d_name);
+		
+		if (suffixLen) {
+			if (nameLen < suffixLen) continue;
+			const char *sub = ent->d_name + nameLen - suffixLen;
+			if ( caseSensitive ? strcmp(suffix, sub)
+				               : heliStringCompareCi(suffix, sub) )
+				continue;
+		}
+		
+		if (bufLen <= d->pathLen + nameLen) {
+			bufLen = d->pathLen + nameLen + 1024;
+			buf = realloc(buf, bufLen);
+		}
+		
+		strcpy(buf + d->pathLen, ent->d_name);
+		
+		if ( (showFiles && fileExists(buf))
+		  || (showDirectories && directoryExists(buf)) )
+			heliStringmapAdd(&d->files, buf, NULL, NULL);
 	}
 	closedir(dir);
 	
@@ -66,6 +114,9 @@ Directory openDirectory(const char *path) {
 	return d;
 }
 
+Directory openDirectory(const char *path)
+	{ return openDirectoryEx(path, NULL, NULL, TRUE, TRUE, TRUE); }
+
 void closeDirectory(Directory directory) {
 	if (!directory) return;
 	heliObjectUnregister(directory);
@@ -76,9 +127,13 @@ void closeDirectory(Directory directory) {
 int directoryGetCount(Directory directory)
 	{ return directory->files.count; }
 
-const char* directoryGet(Directory directory, int i)
+const char* directoryGetFull(Directory directory, int i)
 	{ return (const char*)heliArrayGetKey(&directory->files, i); }
 
+const char* directoryGet(Directory directory, int i) {
+	const char *path = directoryGetFull(directory, i);
+	return path ? path + directory->pathLen : NULL;
+}
 
 int fileExists(const char *path) {
 	struct stat s = {};
@@ -126,22 +181,25 @@ char* heliStringConcat3(const char *a, const char *b, const char *c) {
 	return s;
 }
 
-int heliStringCompareCi(const char *a, const char *b) {
+int heliStringCompareNCi(const char *a, const char *b, size_t n) {
 	if (!a && !b) return 0;
 	if (!a) return -1;
 	if (!b) return 1;
-	while(*a || *b) {
+	while((*a || *b) && n) {
 		if (!a) return -1;
 		if (!b) return 1;
 		char aa = tolower(*a);
 		char bb = tolower(*b);
 		if (aa < bb) return -1;
 		if (bb < aa) return 1;
-		++a, ++b;
+		++a, ++b, --n;
 	}
 	return 0;
 }
 
+int heliStringCompareCi(const char *a, const char *b)
+	{ return heliStringCompareNCi(a, b, SIZE_MAX); }
+
 int heliStringEndsWithLowcase(const char *s, const char *tail) {
 	int ls = strlen(s);
 	int lt = strlen(tail);
diff --git a/src/common.h b/src/common.h
index 49d9da8..c5662f1 100644
--- a/src/common.h
+++ b/src/common.h
@@ -25,9 +25,17 @@ void rotateVector(double *x, double *y, double angle);
 
 
 Directory openDirectory(const char *path);
+Directory openDirectoryEx(
+	const char *path,
+	const char *prefix,
+	const char *suffix,
+	int caseSensitive,
+	int showFiles,
+	int showDirectories );
 void closeDirectory(Directory directory);
 int directoryGetCount(Directory directory);
 const char* directoryGet(Directory directory, int i);
+const char* directoryGetFull(Directory directory, int i);
 
 int fileExists(const char *path);
 int directoryExists(const char *path);
diff --git a/src/private.h b/src/private.h
index 4d818c6..7907119 100644
--- a/src/private.h
+++ b/src/private.h
@@ -43,6 +43,7 @@ char* heliStringCopyLower(const char *x);
 char* heliStringConcat(const char *a, const char *b);
 char* heliStringConcat3(const char *a, const char *b, const char *c);
 int heliStringCompareCi(const char *a, const char *b);
+int heliStringCompareNCi(const char *a, const char *b, size_t n);
 int heliStringEndsWithLowcase(const char *s, const char *tail);
 void heliStringLower(char *x);