initial check-in of file positioning stdio functions

git-svn-id: svn://svn.cc65.org/cc65/trunk@275 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/common/fseek.c

@@ -0,0 +1,28 @@
+/*
+ * fseek.c
+ *
+ * Christian Groessler, 07-Aug-2000
+ */
+
+
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include "_file.h"
+
+
+int fseek(FILE* f, long offset, int whence)
+{
+    long res;
+
+    /* Is the file open? */
+    if ((f->f_flags & _FOPEN) == 0) {
+        _errno = EINVAL;                /* File not open */
+        return 1;
+    }
+
+    res = lseek(f->f_fd, offset, whence);
+    if (res == -1L) return 1;
+    return 0;
+}
+