note 54047 deleted from function.proc-open by cmb

Note Submitter: mib at post dot com ---- I thought it was highly not recommended to fork from your web server? Apart from that, one caveat is that the child process inherits anything that is preserved over fork from the parent (apart from the file descriptors which are explicitly closed). Importantly, it inherits the signal handling setup, which at least with apache means that SIGPIPE is ignored. Child processes that expect SIGPIPE to kill them in order to get sensible pipe handling and not go into a tight write loop will have problems unless they reset SIGPIPE themselves. Similar caveats probably apply to other signals like SIGHUP, SIGINT, etc. Other things preserved over fork include shared memory segments, umask and rlimits.