Very first cut at a klibc-derived C library for com32

1 files changed, 46 insertions, 0 deletions

diff --git a/com32/lib/fopen.c b/com32/lib/fopen.c
new file mode 100644
index 00000000..5c841848
--- /dev/null
+++ b/com32/lib/fopen.c
@@ -0,0 +1,46 @@
+/*
+ * fopen.c
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+/* This depends on O_RDONLY == 0, O_WRONLY == 1, O_RDWR == 2 */
+
+
+FILE *fopen(const char *file, const char *mode)
+{
+  int flags = O_RDONLY;
+  int plus = 0;
+  int fd;
+
+  while ( *mode ) {
+    switch ( *mode ) {
+    case 'r':
+      flags = O_RDONLY;
+      break;
+    case 'w':
+      flags = O_WRONLY|O_CREAT|O_TRUNC;
+      break;
+    case 'a':
+      flags = O_WRONLY|O_CREAT|O_APPEND;
+      break;
+    case '+':
+      plus = 1;
+      break;
+    }
+    mode++;
+  }
+
+  if ( plus ) {
+    flags = (flags & ~(O_RDONLY|O_WRONLY)) | O_RDWR;
+  }
+
+  fd = open(file, flags, 0666);
+
+  if ( fd < 0 )
+    return NULL;
+  else
+    return fdopen(fd, mode);
+}