diff --git a/dir.c b/dir.c
index b50d646..e2e8316 100644
--- a/dir.c
+++ b/dir.c
@@ -81,6 +81,15 @@ dir_t dirOpen(const char *path) {
     return dir;
 }
 
+void dirClose(dir_t ctx) {
+    free(ctx);
+}
+
+bool dirValid(dir_t ctx) {
+    _dir_internal_t *dir = (_dir_internal_t*)ctx;
+    return dir->handle != INVALID_HANDLE_VALUE;
+}
+
 dir_entry_t *dirNext(dir_t ctx) {
     _dir_internal_t *dir = (_dir_internal_t*)ctx;
     strFree(&dir->cur.name);
@@ -90,10 +99,6 @@ dir_entry_t *dirNext(dir_t ctx) {
     return &dir->cur;
 }
 
-void dirClose(dir_t ctx) {
-    free(ctx);
-}
-
 #else
 
 #include <dirent.h>
@@ -127,6 +132,11 @@ void dirClose(dir_t ctx) {
     }
 }
 
+bool dirValid(dir_t ctx) {
+    _dir_internal_t *dir = (_dir_internal_t*)ctx;
+    return dir->handle != NULL;
+}
+
 dir_entry_t *dirNext(dir_t ctx) {
     if(!ctx) return NULL;
     _dir_internal_t *in = (_dir_internal_t *)ctx;
diff --git a/dir.h b/dir.h
index 961509d..4d91bae 100644
--- a/dir.h
+++ b/dir.h
@@ -22,6 +22,8 @@ enum {
 dir_t dirOpen(const char *path);
 void dirClose(dir_t ctx);
 
+bool dirValid(dir_t ctx);
+
 dir_entry_t *dirNext(dir_t ctx);
 
 #ifdef __cplusplus
diff --git a/file.c b/file.c
index 82336b6..4c97989 100644
--- a/file.c
+++ b/file.c
@@ -7,21 +7,20 @@
 #include <windows.h>
 
 static DWORD _toWin32Access(int mode) {
-    switch(mode) {
-        case FILE_READ:  return GENERIC_READ;
-        case FILE_WRITE: return GENERIC_WRITE;
-        case FILE_BOTH:  return GENERIC_READ | GENERIC_WRITE;
-        default: fatal("unrecognized mode: %d", mode); return 0;
-    }
+    if(mode & FILE_READ) return GENERIC_READ;
+    if(mode & FILE_WRITE) return GENERIC_WRITE;
+    if(mode & FILE_BOTH) return GENERIC_READ | GENERIC_WRITE;
+    fatal("unrecognized access mode: %d", mode);
+    return 0;
 }
 
 static DWORD _toWin32Creation(int mode) {
-    switch(mode) {
-        case FILE_READ:  return OPEN_EXISTING;
-        case FILE_WRITE: return OPEN_ALWAYS;
-        case FILE_BOTH:  return OPEN_ALWAYS;
-        default: fatal("unrecognized mode: %d", mode); return 0;
-    }
+    if(mode & FILE_READ) return OPEN_EXISTING;
+    if(mode == (FILE_WRITE | FILE_CLEAR)) return CREATE_ALWAYS;
+    if(mode & FILE_WRITE) return OPEN_ALWAYS;
+    if(mode & FILE_BOTH) return OPEN_ALWAYS;
+    fatal("unrecognized creation mode: %d", mode);
+    return 0;
 }
 
 file_t fileOpen(const char *fname, int mode) {
diff --git a/file.h b/file.h
index 332fd37..f4502a7 100644
--- a/file.h
+++ b/file.h
@@ -8,7 +8,10 @@ extern "C" {
 #include "str.h"
 
 enum {
-    FILE_READ, FILE_WRITE, FILE_BOTH
+    FILE_READ  = 1 << 0, 
+    FILE_WRITE = 1 << 1, 
+    FILE_CLEAR = 1 << 2, 
+    FILE_BOTH  = 1 << 3
 };
 
 typedef struct {
diff --git a/str.c b/str.c
index 9feb60a..87383ee 100644
--- a/str.c
+++ b/str.c
@@ -263,6 +263,18 @@ str_t strToLower(str_t ctx) {
     return str;
 }
 
+void strUpper(str_t *ctx) {
+    for(size_t i = 0; i < ctx->len; ++i) {
+        ctx->buf[i] = (char)toupper(ctx->buf[i]);
+    }
+}
+
+str_t strToUpper(str_t ctx) {
+    str_t str = strDup(ctx);
+    strUpper(&str);
+    return str;
+}
+
 // == STRVIEW_T ====================================================
 
 strview_t strvInit(const char *cstr) {
diff --git a/str.h b/str.h
index 305d637..1950b72 100644
--- a/str.h
+++ b/str.h
@@ -68,6 +68,9 @@ strview_t strSubview(str_t *ctx, size_t pos, size_t len);
 void strLower(str_t *ctx);
 str_t strToLower(str_t ctx);
 
+void strUpper(str_t *ctx);
+str_t strToUpper(str_t ctx);
+
 #ifdef STR_TESTING
 void strTest(void);
 #endif
diff --git a/strstream.c b/strstream.c
index 76f56e8..8639f52 100644
--- a/strstream.c
+++ b/strstream.c
@@ -534,7 +534,7 @@ void ostrAppenddouble(str_ostream_t *ctx, double val) {
 }
 
 void ostrAppendview(str_ostream_t *ctx, strview_t view) {
-    if((ctx->allocated - ctx->size) < view.len) {
+    if((ctx->allocated - ctx->size) <= view.len) {
         _ostrRealloc(ctx, view.len + 1);
     }
     memcpy(ctx->buf + ctx->size, view.buf, view.len);