From d75de5f423aea018067486fd81a96a7abb70abc5 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sun, 23 Oct 2022 11:12:54 +0200
Subject: [PATCH] libc: Partially implement ungetc

---
 libs/libc/src/file.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/libs/libc/src/file.cpp b/libs/libc/src/file.cpp
index 74507216..d8091b5a 100644
--- a/libs/libc/src/file.cpp
+++ b/libs/libc/src/file.cpp
@@ -170,9 +170,14 @@ extern "C"
         return fgetc(stdin);
     }
 
-    int ungetc(int, FILE*)
+    int ungetc(int c, FILE* stream)
     {
-        NOT_IMPLEMENTED("ungetc");
+        if (stream->f_bufoff > 0)
+        {
+            stream->f_bufoff--;
+            stream->f_buf[stream->f_bufoff] = (char)c;
+        }
+        else { NOT_IMPLEMENTED("ungetc with buffer that has not been read"); }
     }
 
     int ferror(FILE* stream)