[parisc-linux] Re: pipes

[Alan Modra]

On Thu, 22 Feb 2001, Richard Hirst wrote:

> Don't think so.  The read is issued at 14:36:08, no data is available,
> so 10 seconds later the alarm goes off, and read returns -512.  Strace
> completes that line of output and reports the SIGALRM.

Ah, thanks for the clarification.  So it comes back to data being mangled
in the pipe or somesuch.

Hmm, strace -f now works with your mods to the kernel, so now I can look
at the other end.  

131   22:37:47 write(5, "cd /scsi/tmp\nfile=sys/stat.h\nif ( test  -r types/vxTypesOld.h ) > /dev/null 2>&1\nthen echo TRUE\nelse echo FALSE\nfi\n\necho\necho ShElL-OuTpUt-HaS-bEeN-cOmPlEtEd\n", 158 <unfinished ...>
132   22:37:47 read(0, "cd /scsi/tmp\nfile=sys/stat.h\nif ( test  -r types/vxTypesOld.h ) > /dev/null 2>&1\nthen echo TRUE\nelse echo FALSE\nfi\n\necho\necho ShElL-OuTpUt-HaS-bEeN-cOmPlEtEUUUU\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\367\4\0\0\0\0\0PUU\0\0\0\0\0\0"..., 156) = 558544
132   22:37:47 chdir("/scsi/tmp")       = 0

Bingo.  Look at that read.