Mandeep Sandhu (Mandeep_Sandhu@xxxxxxxxxxx) wrote: > hi all, > > I had written a small character driver under kernel 2.4.20. > For starters I had implemented it's read method only. This > would put a constant string "hello" into the user-space > buffer. The problem I'm seeing is that when i "cat" my device > it does not print anything on the console (i.e cat and not the > printk's in my driver...they get printed fine!). strace of cat > shows that it calls my drivers read method twice...first time > i copy the constant string into the user's buffer and return the > bytes copied....and on the second invocation i return 0 as there's > nothing more to read. strace shows cat writing out to the std. > output after the first read....but nothing comes on the console!! > if I put '\n' character in my constant string it prints out the > string correctly! I'm guessing the newline char causes the o/p > stream to be flushed....is this expected behavior?? > > TIA, > -mandeep If in your userland program, you print with a printf, it is normal, it can not be print... man flush ~Christophe -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
