On 8/1/19 3:36 PM, qw wrote: > Are those functions thread-safe, i.e. fprintf() and fflush() ? "man fprintf" has the answer. "yum install man-pages" if you do not have it installed already. Spoiler: yes, they are thread-safe, but fprintf may act strange if you change your locale while it is running. Regards. -- Roberto Ragusa mail at robertoragusa.it