> Just to get some evidence at hand - could some owners of
> different platforms compile and run the attached little C
> source please?
$ uname -srm
FreeBSD 4.1.1-STABLE
$ ./jan
Pipe buffer is 16384 bytes
Sys-V message queue buffer is 2048 bytes
$ uname -srm
NetBSD 1.5 alpha
$ ./jan
Pipe buffer is 4096 bytes
Sys-V message queue buffer is 2048 bytes
$ uname -srm
NetBSD 1.5_BETA2 i386
$ ./jan
Pipe buffer is 4096 bytes
Sys-V message queue buffer is 2048 bytes
$ uname -srm
NetBSD 1.4.2 i386
$ ./jan
Pipe buffer is 4096 bytes
Sys-V message queue buffer is 2048 bytes
$ uname -srm
NetBSD 1.4.1 sparc
$ ./jan
Pipe buffer is 4096 bytes
Bad system call (core dumped) # no SysV IPC in running kernel
$ uname -srm
HP-UX B.11.11 9000/800
$ ./jan
Pipe buffer is 8192 bytes
Sys-V message queue buffer is 16384 bytes
$ uname -srm
HP-UX B.11.00 9000/813
$ ./jan
Pipe buffer is 8192 bytes
Sys-V message queue buffer is 16384 bytes
$ uname -srm
HP-UX B.10.20 9000/871
$ ./jan
Pipe buffer is 8192 bytes
Sys-V message queue buffer is 16384 bytes
HP-UX can also use STREAMS based pipes if the kernel parameter
streampipes is set. Using STREAMS based pipes increases the pipe
buffer size by a lot:
# uname -srm
HP-UX B.11.11 9000/800
# ./jan
Pipe buffer is 131072 bytes
Sys-V message queue buffer is 16384 bytes
# uname -srm
HP-UX B.11.00 9000/800
# ./jan
Pipe buffer is 131072 bytes
Sys-V message queue buffer is 16384 bytes
Regards,
Giles