From: Tadeusz Bochan Date: 2011-02-21T05:18:29+09:00 Subject: Re: posix_mq : Problem installing on HPUX Hello Peter, I searched /usr/include and could not find anything with MQ_IO*, particularly not in mqueue.h. I don't have a linux available to compare. I have progressed with the problem though, albeit using the 'throwing darts' technique of problem solving. source: http://bogomips.org/ruby_posix_mq.git/tree/ext/posix_mq/posix_mq.c In posix_mq.c there was only one reference to MQ_IO_NIL_P so I changed it: if (mq->des != MQD_INVALID && MQ_IO_NIL_P(mq)) { to if (mq->des != MQD_INVALID && NIL_P(mq)) { and that eliminated that problem, although I don't know what impact this will have at runtime. Seems to work. The next problem was while testing the receive method. I got the Unresolved symbol : rb_str_set_len So I changed : static void rb_18_str_set_len(VALUE str, long len) to static void rb_str_set_len(VALUE str, long len) And so far it all seems to be working. So I made 3 changes : 1) Commenting out the syntax error on the 'if' statement 2) Changing the reference to MQ_IO_NIL_P to NIL_P 3) Changing rb_18_str_set_len to rb_str_set_len and still none the wiser about C programming !! -- Posted via http://www.ruby-forum.com/.