util: add comment explaining hostname_is_valid()

[elogind.git] / CODING_STYLE

diff --git a/CODING_STYLE b/CODING_STYLE
index 598d241b2baa048c1bc18644ade20ea9dcfb3d49..0b1f809e79717812c0fdd007e1ef5786a5f4e916 100644 (file)
--- a/CODING_STYLE
+++ b/CODING_STYLE
@@ -182,7 +182,16 @@
   is_main_thread() to detect whether the calling thread is the main
   thread.
 
-- Option parsing:
+- Command line option parsing:
   - Do not print full help() on error, be specific about the error.
   - Do not print messages to stdout on error.
   - Do not POSIX_ME_HARDER unless necessary, i.e. avoid "+" in option string.
+
+- Do not write functions that clobber call-by-reference variables on
+  failure. Use temporary variables for these cases and change the
+  passed in variables only on success.
+
+- When you allocate a file descriptor, it should be made O_CLOEXEC
+  right from the beginning, as none of our files should leak to forked
+  binaries by default. Hence, whenever you open a file, O_CLOEXEC must
+  be specified, right from the beginning.